As filed with the Securities and Exchange Commission on June 3, 1997
                          Registration No. 333-_______


                     U.S. SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                    Form S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933

                           TRIMBLE NAVIGATION LIMITED
             (Exact name of registrant as specified in its charter)


              California                            94-2802192
 (State or other jurisdiction of        (I.R.S. Employer Identification No.)
  incorporation or organization)        
                                            
    

                              645 North Mary Avenue
                           Sunnyvale, California 94088
                    (Address of Principal Executive Offices)


                             1993 Stock Option Plan
                            (Full title of the plan)


                               Charles R. Trimble
                                    President
                           Trimble Navigation Limited
                              645 North Mary Avenue
                           Sunnyvale, California 94088
                     (Name and address of agent for service)
                                 (408) 481-8000
           Telephone number, including area code, of agent for service



                                    Copy to:

                             John B. Goodrich, Esq.
                       Wilson, Sonsini, Goodrich & Rosati
                            Professional Corporation
                               650 Page Mill Road
                        Palo Alto, California 94304-1050

<TABLE>
<CAPTION>

                         CALCULATION OF REGISTRATION FEE
     ------------------------ ----------------- ------------------ --------------- ------------------
     <S>   <C>                    <C>          <C>                 <C>              <C>    
            Title of               Amount           Proposed          Proposed         Amount of
          Securities to            to be        Maximum Offering      Maximum        Registration
          be Registered          Registered      Price Per Share     Aggregate            Fee
                                                                   Offering Price
     ------------------------ ----------------- ------------------ --------------- ------------------
     ------------------------ ----------------- ------------------ --------------- ------------------
     Common Stock
     - 1993 Stock Option           600,000         $13.563(1)      $9,337,800(1)     $2,830
     Plan
     TOTALS                        600,000                         $9,337,800        $2,830
                                   =======
     ------------------------ ----------------- ------------------ --------------- ------------------
<FN>

     (1)    Estimated  solely for the purpose of  calculating  the amount of the
            registration  fee on the  basis of the  average  of the high and low
            price reported by the Nasdaq National Market System on May 27, 1997.

</FN>
</TABLE>

                                       II1


<PAGE>

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


     The  registrant  hereby  incorporates  by  reference  the  contents  of the
following  Registration  Statements on Form S-8: Registration No. 33-39647 dated
April 2, 1991,  Registration  No. 34-57522 dated January 28, 1993,  Registration
No. 33-78502 dated May 3, 1994, Registration No. 33-91858 dated May 3, 1995, and
Registration No. 333-04670 dated May 3, 1996.


 Item 8.  Exhibits.

          Exhibit
           Number

            5.1  Opinion of Wilson, Sonsini, Goodrich & Rosati, Professional 
                 Corporation

            10.1  1993 Stock Option Plan

            23.1  Consent of Ernst & Young LLP, Independent Auditors

            23.2  Consent of Wilson, Sonsini, Goodrich & Rosati, Professional 
                  Corporation (Contained in Exhibit 5.1)

            24.1  Power of Attorney (See Page II-3)




                                      II2




<PAGE>


                                   SIGNATURES

     The Registrant

     Pursuant to the  requirements of the Securities Act of 1933, the registrant
certifies  that it has  reasonable  grounds to believe  that it meets all of the
requirements  for  filing  on Form S-8 and has  duly  caused  this  registration
statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized, in the City of Sunnyvale, State of California, on May 29, 1997.


                                    TRIMBLE NAVIGATION LIMITED


                                     By:  /s/Charles R. Trimble
                                          Charles R. Trimble,
                                          President



                                POWER OF ATTORNEY

     KNOW ALL  PERSONS  BY THESE  PRESENTS,  that each  person  whose  signature
appears  below  constitutes  and appoints  Charles R. Trimble and Dennis R. Ing,
jointly  and   severally,   his   attorney-in-fact,   each  with  the  power  of
substitution,  for him in any and all capacities, to sign any amendments to this
Registration  Statement on Form S-8, and to file the same, with exhibits thereto
and other  documents in connection  therewith,  with the Securities and Exchange
Commission,  hereby ratifying and confirming all that said attorney-in-fact,  or
his substitute or substitutes, may do or cause to be done by virtue hereof.



                                      II3


<PAGE>


     Pursuant  to  the   requirements  of  the  Securities  Act  of  1933,  this
registration  statement  has  been  signed  by  the  following  persons  in  the
capacities and on the dates indicated.

    
     Signature                     Title                            Date

 /s/Charles R. Trimble   President, Chief Executive Officer     May 29, 1997
(Charles R. Trimble)    (Principal Executive Officer) and
                         Director
     
- -------------------------------------- ---------------------------------------- 
- -------------------------------------- ---------------------------------------- 

/s/Dennis R. Ing        Vice President - Finance and Chief      May 29, 1997
(Dennis R. Ing)         Financial Officer (Principal
                        Financial Officer and Principal
                        Accounting Officer)
- -------------------------------------- -----------------------------------------
- -------------------------------------- -----------------------------------------

/s/Robert S. Cooper     Director                                May 28, 1997
(Robert S. Cooper)                                  
     
  
- -------------------------------------- -----------------------------------------
- -------------------------------------- -----------------------------------------

/s/William Hart           Director                               May 29, 1997
(William Hart)
                                                                         
    
- -------------------------------------- -----------------------------------------
- -------------------------------------- -----------------------------------------
 
/s/Bradford W. Parkinson  Director                               May 28, 1997
(Bradford W. Parkinson)                                                         
   

     
- -------------------------------------- -----------------------------------------


                                       II4


<PAGE>




                                INDEX TO EXHIBITS

          Exhibit             Description
          Number

          5.1       Opinion of Wilson, Sonsini, Goodrich & Rosati,
                    Professional Corporation
    
          10.2      1993 Stock Option Plan
     

          23.1      Consent of Ernst & Young LLP, Independent Auditors
     
          23.2      Consent of Wilson, Sonsini, Goodrich & Rosati,
                    Professional Corporation (Contained in Exhibit 5.1)

          24.1      Power of Attorney (see Page II-3)
     


<PAGE>







                                                            EXHIBIT 5.1


                                  May 29, 1997


     TRIMBLE NAVIGATION LIMITED
     645 North Mary Avenue
     Sunnyvale, California 94088

            RE:    REGISTRATION STATEMENT ON FORM S-8

     Ladies and Gentlemen:

     We have examined the Registration  Statement on Form S-8 to be filed by you
with the  Securities  and  Exchange  Commission  on or about  May 29,  1997 (the
"Registration  Statement"),  in  connection  with  the  registration  under  the
Securities  Act of 1933,  as amended,  of 600,000  shares of your  Common  Stock
reserved for issuance  under the 1993 Stock  Option Plan (the  "Plan").  As your
legal counsel,  we have examined the proceedings  taken and proposed to be taken
in connection  with the issuance,  sale,  and payment of  consideration  for the
shares to be issued under the Plan.

     It is our opinion that,  when issued and sold in the manner  referred to in
the Plan and pursuant to the  agreements  which  accompany the Plan,  the shares
will be legally and validly issued, fully paid, and non-assessable.

     We  consent to the use of this  opinion  as an exhibit to the  Registration
Statement and further  consent to the use of our name wherever  appearing in the
Registration Statement and any amendments thereto.

                                             Very truly yours,

                                              WILSON, SONSINI, GOODRICH & ROSATI
                                              Professional Corporation


                                              By:  /s/ John B. Goodrich

                                                   John B. Goodrich


<PAGE>


                                                             EXHIBIT 10.1

                           TRIMBLE NAVIGATION LIMITED
                             1993 STOCK OPTION PLAN
                         (amended as of March 19, 1997)

     I.  Purposes  of the Plan.  The  purposes of this Stock  Option Plan are to
attract and retain the best  available  personnel for  positions of  substantial
responsibility, to provide additional incentive to the Employees and Consultants
of the Company and to promote the success of the Company's business.

     Options  granted  hereunder  may  be  either  Incentive  Stock  Options  or
Nonstatutory  Stock Options,  at the discretion of the Board and as reflected in
the terms of the written option agreement.

     I. Definitions. As used herein, the following definitions shall apply:

     A.  "Administrator"  means  the  Board or any of its  Committees  appointed
pursuant to Section 4 of the Plan.

     A. "Board"  shall mean the  Committee,  if one has been  appointed,  or the
Board of Directors of the Company, if no Committee is appointed.

     A. "Code" shall mean the Internal Revenue Code of 1986, as amended.

     A. "Committee" shall mean the Committee appointed by the Board of Directors
in accordance with paragraph (a) of Section 4 of the Plan, if one is appointed.

     A. "Common Stock" shall mean the Common Stock of the Company.

     A.  "Company"  shall  mean  Trimble   Navigation   Limited,   a  California
corporation.


     A. "Consultant"  shall mean any person who is engaged by the Company or any
Parent or Subsidiary to render  consulting  services and is compensated for such
consulting  services,  and any director of the Company  whether  compensated for
such  services  or not,  provided  that the term  Consultant  shall not  include
directors  who are  not  compensated  for  their  services  or are  paid  only a
director's fee by the Company.

     A. "Continuous Status as an Employee or Consultant"  shall mean the absence
of any  interruption  or  termination  of service as an Employee or  Consultant.
Continuous  Status  as  an  Employee  or  Consultant  shall  not  be  considered
interrupted  in the case of sick leave,  military  leave,  or any other leave of
absence  approved by the  Company or any Parent or  Subsidiary  of the  Company;
provided  that  such  leave  is for a  period  of  not  more  than  90  days  or
reemployment  upon the  expiration  of such leave is  guaranteed  by contract or
statute.

     A.  "Employee"  shall mean any person,  including  officers and  directors,
employed by the Company or any Parent or Subsidiary of the Company.  The payment
of a  director's  fee by the  Company  shall  not be  sufficient  to  constitute
"employment" by the Company.

     A. "Exchange Act" means the Securities Exchange Act of 1934, as amended.

     A. "Fair Market  Value"  means,  as of any date,  the value of Common Stock
determined as follows:

     1. If the Common  Stock is listed on any  established  stock  exchange or a
national market system including  without  limitation the National Market System
of the National  Association of Securities  Dealers,  Inc.  Automated  Quotation
("NASDAQ")  System,  its Fair Market Value shall be the closing  sales price for
such stock (or the  closing  bid, if no sales were  reported,  as quoted on such
system  or  exchange  for the  last  market  trading  day  prior  to the time of
determination)  as reported in the Wall Street  Journal or such other  source as
the Administrator deems reliable;

     1. If the  Common  Stock is quoted  on the  NASDAQ  System  (but not on the
National Market System thereof) or regularly  quoted by a recognized  securities
dealer but selling  prices are not reported,  its Fair Market Value shall be the
mean between the high and low asked prices for the Common Stock or;

     1. In the absence of an established  market for the Common Stock,  the Fair
Market Value thereof shall be determined in good faith by the Administrator.

     A. "Incentive  Stock Option" shall mean an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code.

     A. "Nonstatutory Stock Option" shall mean an Option not intended to qualify
as an Incentive Stock Option.

     A. "Option" shall mean a stock option granted pursuant to the Plan.

     A. "Optioned Stock" shall mean the Common Stock subject to an Option.

     A. "Optionee" shall mean an Employee or Consultant who receives an Option.

     A.  "Parent"  shall mean a "parent  corporation",  whether now or hereafter
existing, as defined in Section 424(e) of the Code.

     A. "Plan" shall mean this 1993 Stock Option Plan.

     A.  "Share"  shall  mean a  share  of the  Common  Stock,  as  adjusted  in
accordance with Section 11 of the Plan.
     B.  "Subsidiary"  shall mean a  "subsidiary  corporation",  whether  now or
hereafter existing, as defined in Section 424(f) of the Code.

     I.  Stock Subject to the Plan.  Subject to the  provisions of Section 11 of
the Plan, the maximum  aggregate number of shares which may be optioned and sold
under  the  Plan  is  3,200,000  shares  of  Common  Stock.  The  Shares  may be
authorized, but unissued, or reacquired Common Stock.

     If an Option should expire or become  unexercisable  for any reason without
having been exercised in full, the unpurchased Shares which were subject thereto
shall,  unless the Plan shall have been terminated,  become available for future
grant under the Plan.  Notwithstanding  any other provision of the Plan,  shares
issued  under the Plan and later  repurchased  by the  Company  shall not become
available for future grant or sale under the Plan.

     I. Administration of the Plan.

     A. Procedure.

     1.  Multiple  Administrative  Bodies.  The  Plan  may  be  administered  by
different   Committees  with  respect  to  different  groups  of  Employees  and
Consultants.

     1. Section 162(m). To the extent that the Administrator determines it to be
desirable  to  qualify   Options   granted   hereunder   as   "performance-based
compensation"  within the meaning of Section  162(m) of the Code, the Plan shall
be  administered  by a Committee of two or more "outside  directors"  within the
meaning of Section 162(m) of the Code.

     1. Rule 16b-3. To the extent desirable to qualify transactions hereunder as
exempt  under Rule  16b-3,  the  transactions  contemplated  hereunder  shall be
structured to satisfy the requirements for exemption under Rule 16b-3.

     A.  Powers of the Administrator.  Subject to the provisions of the Plan and
in the case of a Committee,  the specific duties  delegated by the Board to such
Committee, the Administrator shall have the authority, in its discretion:

     1. to determine  the Fair Market Value of the Common  Stock,  in accordance
with Section 2(k) of the Plan;

     1. to select the  officers,  Consultants  and Employees to whom Options may
from time to time be granted hereunder;

     1. to determine whether and to what extent Options are granted hereunder;

     1. to determine  the number of shares of Common Stock to be covered by each
such award granted hereunder;

     2. to approve forms of agreement for use under the Plan;

     1. to determine the terms and conditions,  not inconsistent  with the terms
of the Plan, of any award granted hereunder (including,  but not limited to, the
share price and any  restriction or limitation,  or any vesting  acceleration or
waiver of  forfeiture  restrictions  regarding  any Option  and/or the shares of
Common  Stock  relating  thereto,  based  in each  case on such  factors  as the
Administrator shall determine, in its sole discretion);

     1. to  determine  whether  and under  what  circumstances  an Option may be
settled in cash under subsection 9(e) instead of Common Stock;

     1. to determine whether, to what extent and under what circumstances Common
Stock and other  amounts  payable with respect to an award under this Plan shall
be  deferred  either  automatically  or  at  the  election  of  the  participant
(including  providing  for and  determining  the  amount,  if any, of any deemed
earnings on any deferred amount during any deferral period);

     1. to reduce  the  exercise  price of any Option to the then  current  Fair
Market Value if the Fair Market Value of the Common Stock covered by such Option
shall have declined since the date the Option was granted; and

     A.  Effect of Administrator's Decision.  All decisions,  determinations and
interpretations of the Administrator shall be final and binding on all Optionees
and any other holders of any Options.

     A. Grant Limits. The following limitations shall apply to grants of Options
under the Plan:

     1. No employee shall be granted, in any fiscal year of the Company, Options
under the Plan to purchase more than 100,000  Shares,  provided that the Company
may make an additional  one-time  grant of up to 250,000  Shares to  newly-hired
Employees.

     1.  The  foregoing   limitations  shall  be  adjusted   proportionately  in
connection  with any change in the  Company's  capitalization  as  described  in
Section 11.
     1. If an Option is cancelled  (other than in connection  with a transaction
described in  Section 11),  the  cancelled  Option shall be counted  against the
limits set forth in Section 4(d)(i).  For this purpose, if the exercise price of
an Option is reduced,  the transaction  will be treated as a cancellation of the
Option and the grant of a new Option.

     I. Eligibility.

     A. Nonstatutory Stock Options may be granted only to Employees,  Directors,
and  Consultants.  Incentive Stock Options may be granted only to Employees.  An
Employee,  Director,  or Consultant who has been granted an Option may, if he is
otherwise eligible, be granted an additional Option or Options.

     A. Each Option  shall be  designated  in the written  option  agreement  as
either an  Incentive  Stock  Option or a  Nonstatutory  Stock  Option.  However,
notwithstanding such designations,  to the extent that the aggregate Fair Market
Value of the Shares with respect to which Options  designated as Incentive Stock
Options are  exercisable  for the first time by any Optionee during any calendar
year  (under  all plans of the  Company  or any  Parent or  Subsidiary)  exceeds
$100,000, such excess Options shall be treated as Nonstatutory Stock Options.

     A. For purposes of  Section 5(b),  Incentive  Stock  Options shall be taken
into account in the order in which they were granted,  and the Fair Market Value
of the Shares shall be determined as of the time the Option with respect to such
Shares is granted.

     A. The Plan shall not confer upon any  Optionee  any right with  respect to
continuation  of  employment or consulting  relationship  with the Company,  nor
shall it interfere in any way with his right or the Company's right to terminate
his employment or consulting relationship at any time, with or without cause.

     I. Term of Plan.  The Plan shall become effective upon the earlier to occur
of its adoption by the Board of Directors or its approval by the shareholders of
the Company as described in Section 18 of the Plan. It shall  continue in effect
for a term of ten (10) years unless  sooner  terminated  under Section 14 of the
Plan.

     I. Term of Option. The term of each Option shall be ten (10) years from the
date of grant  thereof or such  shorter  term as may be  provided  in the Option
Agreement.  However,  in the case of an  Incentive  Stock  Option  granted to an
Optionee who, at the time the Option is granted,  owns stock  representing  more
than ten  percent  (10%) of the  voting  power  of all  classes  of stock of the
Company or any Parent or  Subsidiary,  the term of the Option  shall be five (5)
years from the date of grant  thereof or such shorter term as may be provided in
the Option Agreement.

     I. Exercise Price and Consideration.

     A. The per Share  exercise  price for the Shares to be issued  pursuant  to
exercise of an Option  shall be such price as is  determined  by the Board,  but
shall be subject to the following:

     1. In the case of an Incentive Stock Option

     a) granted to an Employee  who, at the time of the grant of such  Incentive
Stock Option,  owns stock representing more than ten percent (10%) of the voting
power of all  classes of stock of the Company or any Parent or  Subsidiary,  the
per Share exercise price shall be no less than 110% of the Fair Market Value per
Share on the date of grant.

     a) granted to any Employee,  the per Share  exercise price shall be no less
than 100% of the Fair Market Value per Share on the date of grant.

     1. In the case of a Nonstatutory Stock Option, the per Share exercise price
shall be determined by the  Administrator.  In the case of a Nonstatutory  Stock
Option  intended  to  qualify  as  "performance-based  compensation"  within the
meaning of Section  162(m) of the Code, the per Share exercise price shall be no
less than 100% of the Fair Market Value per Share on the date of grant.

     (iii)  Notwithstanding  the  foregoing,  Options may be granted  with a per
Share exercise price of less than 100% of the Fair Market Value per Share on the
date of grant pursuant to a merger or other corporate transaction.

     A. The  consideration  to be paid for the Shares to be issued upon exercise
of an  Option,  including  the method of  payment,  shall be  determined  by the
Administrator  and may consist entirely of (1) cash,  (2) check,  (3) promissory
note, (4) other Shares which (x) either have been owned by the Optionee for more
than six  months on the date of  surrender  or were not  acquired,  directly  or
indirectly,  from the  Company,  and (y) have a Fair Market Value on the date of
surrender  equal to the aggregate  exercise price of the Shares as to which said
Option shall be exercised, (5) authorization from the Company to retain from the
total number of Shares as to which the Option is exercised that number of Shares
having a Fair Market Value on the date of exercise  equal to the exercise  price
for the total number of Shares as to which the Option is exercised, (6) delivery
of a properly executed exercise notice together with irrevocable instructions to
a broker to promptly  deliver to the Company the amount of sale or loan proceeds
required to pay the exercise price,  (7) delivery of an irrevocable subscription
agreement for the Shares which  irrevocably  obligates the option holder to take
and pay for the Shares not more than twelve months after the date of delivery of
the  subscription  agreement,  (8) any  combination of the foregoing  methods of
payment,  (9) or such other consideration and method of payment for the issuance
of  Shares  to the  extent  permitted  under  Applicable  Laws.  In  making  its
determination  as to the  type of  consideration  to  accept,  the  Board  shall
consider if  acceptance  of such  consideration  may be  reasonably  expected to
benefit the Company.

     I. Exercise of Option.

     A.  Procedure for Exercise;  Rights as a  Shareholder.  Any Option  granted
hereunder  shall be  exercisable  at such  times and under  such  conditions  as
determined  by the Board,  including  performance  criteria  with respect to the
Company and/or the Optionee,  and as shall be permissible under the terms of the
Plan.

     An Option may not be exercised for a fraction of a Share.

     An Option  shall be  deemed to be  exercised  when  written  notice of such
exercise  has been  given to the  Company  in  accordance  with the terms of the
Option by the person  entitled to exercise  the Option and full  payment for the
Shares with  respect to which the Option is exercised  has been  received by the
Company.  Full  payment  may,  as  authorized  by  the  Board,  consist  of  any
consideration  and method of payment  allowable under  Section 8(b) of the Plan.
Until the issuance (as  evidenced by the  appropriate  entry on the books of the
Company or of a duly  authorized  transfer  agent of the  Company)  of the stock
certificate evidencing such Shares, no right to vote or receive dividends or any
other rights as a  shareholder  shall exist with respect to the Optioned  Stock,
notwithstanding the exercise of the Option. The Company shall issue (or cause to
be issued)  such stock  certificate  promptly  upon  exercise of the Option.  No
adjustment  will be made for a dividend or other right for which the record date
is prior to the date the stock  certificate  is issued,  except as  provided  in
Section 11 of the Plan.

     Exercise  of an Option in any  manner  shall  result in a  decrease  in the
number of Shares which  thereafter  may be  available,  both for purposes of the
Plan and for sale  under  the  Option,  by the  number of Shares as to which the
Option is exercised.

     A.  Termination of Status  as an  Employee or Consultant.  In the  event of
termination of an Optionee's  Continuous Status as an Employee or Consultant (as
the case may be),  such  Optionee may, but only within thirty (30) days (or such
other period of time, not exceeding three (3) months in the case of an Incentive
Stock Option or six (6) months in the case of a Nonstatutory Stock Option, as is
determined  by the Board)  after the date of such  termination  (but in no event
later than the date of expiration of the term of such Option as set forth in the
Option  Agreement),  exercise  his Option to the extent that he was  entitled to
exercise  it at the  date of such  termination.  To the  extent  that he was not
entitled to exercise the Option at the date of such  termination,  or if he does
not exercise  such Option  (which he was  entitled to exercise)  within the time
specified herein, the Option shall terminate.

     A. Disability of Optionee.  Notwithstanding  the provisions of Section 9(b)
above,  in the event of  termination  of an Optionee's  Continuous  Status as an
Employee or  Consultant as a result of his total and  permanent  disability  (as
defined in Section 22(e)(3) of the Code), he may, but only within six (6) months
(or such other period of time not exceeding  twelve (12) months as is determined
by the Board) from the date of such  termination (but in no event later than the
date of  expiration  of the  term of such  Option  as set  forth  in the  Option
Agreement),  exercise his Option to the extent he was entitled to exercise it at
the date of such termination. To the extent that he was not entitled to exercise
the Option at the date of  termination,  or if he does not exercise  such Option
(which he was entitled to exercise) within the time specified herein, the Option
shall terminate.

     A. Death of Optionee. In the event of the death of an Optionee:

     1.  during  the  term of the  Option  who is at the  time of his  death  an
Employee or  Consultant  of the  Company  and who shall have been in  Continuous
Status as an Employee or Consultant  since the date of grant of the Option,  the
Option may be  exercised,  at any time within  twelve (12) months  following the
date of death (but in no event later than the date of  expiration of the term of
such Option as set forth in the Option  Agreement),  by the Optionee's estate or
by a person  who  acquired  the  right to  exercise  the  Option by  bequest  or
inheritance,  but only to the  extent of the right to  exercise  that would have
accrued had the Optionee  continued living and remained in Continuous  Status as
an Employee or Consultant twelve (12) months after the date of death, subject to
the limitation set forth in Section 5(b); or 2. within thirty (30) days (or such
other  period of time not  exceeding  three (3) months as is  determined  by the
Board) after the termination of Continuous  Status as an Employee or Consultant,
the Option may be exercised, at any time within twelve (12) months following the
date of death (but in no event later than the date of  expiration of the term of
such Option as set forth in the Option  Agreement),  by the Optionee's estate or
by a person  who  acquired  the  right to  exercise  the  Option by  bequest  or
inheritance, but only to the extent of the right to exercise that had accrued at
the date of termination.

     A. Buyout  Provisions.  The  Administrator may at any time offer to buy out
for a payment in cash or Shares,  an Option  previously  granted,  based on such
terms and conditions as the Administrator shall establish and communicate to the
Optionee at the time that such offer is made.

     I.  Non-Transferability of Options.  Options  may  not  be  sold,  pledged,
assigned,  hypothecated,  transferred or disposed of in any manner other than by
will or by the laws of descent  and  distribution  or  pursuant  to a  qualified
domestic  relations  order as  defined  by the  Code or Title I of the  Employee
Retirement  Income Security Act, or the rules  thereunder.  The designation of a
beneficiary  by an Optionee  does not  constitute  a transfer.  An Option may be
exercised,  during the  lifetime  of the  Optionee,  only by the  Optionee  or a
transferee permitted by this Section 10.

     I.  Adjustments Upon Changes in Capitalization  or  Merger.  Subject to any
required  action by the  shareholders  of the  Company,  the number of shares of
Common Stock  covered by each  outstanding  Option,  and the number of shares of
Common Stock which have been  authorized  for issuance  under the Plan but as to
which no Options have yet been  granted or which have been  returned to the Plan
upon  cancellation or expiration of an Option, as well as the price per share of
Common Stock covered by each such outstanding  Option,  shall be proportionately
adjusted for any  increase or decrease in the number of issued  shares of Common
Stock  resulting  from a stock  split,  reverse  stock  split,  stock  dividend,
combination or  reclassification  of the Common Stock,  or any other increase or
decrease in the number of issued shares of Common Stock effected without receipt
of  consideration  by the Company;  provided,  however,  that  conversion of any
convertible securities of the Company shall not be deemed to have been "effected
without receipt of  consideration."  Such adjustment shall be made by the Board,
whose  determination  in that respect  shall be final,  binding and  conclusive.
Except as  expressly  provided  herein,  no issuance by the Company of shares of
stock of any class, or securities convertible into shares of stock of any class,
shall affect, and no adjustment by reason thereof shall be made with respect to,
the number or price of shares of Common Stock subject to an Option.

     In the event of the proposed dissolution or liquidation of the Company, the
Board  shall  notify  the  Optionee  at least  fifteen  (15) days  prior to such
proposed action. To the extent it has not been previously exercised,  the Option
will terminate immediately prior to the consummation of such proposed action. In
the event of a merger  of the  Company  with or into  another  corporation,  the
Option shall be assumed or an  equivalent  option shall be  substituted  by such
successor  corporation or a parent or subsidiary of such successor  corporation.
In the even the successor corporation does not agree to assume the option or the
substitute and equivalent option, the Board shall, in lieu of such assumption or
substitution, provide for the Optionee to have the right to vest in and exercise
the Option as to all of the  Optioned  Stock,  including  Shares as to which the
Option  would not  otherwise  be vested or  exercisable.  If the Board  makes an
Option fully vested and exercisable in lieu of assumption or substitution in the
event of a merger,  the Board shall notify the Optionee that the Option shall be
fully vested and  exercisable for a period of fifteen (15) days from the date of
such notice,  and the Option will  terminate upon the expiration of such period.
If,  in such a  merger,  the  Option  is  assumed  or an  equivalent  option  is
substituted  by such  successor  corporation  or a parent or  subsidiary of such
successor corporation,  and if during a one-year period after the effective date
of such merger, the Optionee's Continuous Status as an Employee or Consultant is
terminated  for any reason other than the  Optionee's  voluntary  termination of
such  relationship,  then the Optionee  shall have the right within  thirty days
thereafter  to exercise  the Option as to all of the Optioned  Stock,  including
Shares as to which the Option would not be otherwise  exercisable,  effective as
of the date of such termination.

     I.  Stock  Withholding  to  Satisfy  Withholding  Tax  Obligations.  At the
discretion of the Administrator,  Optionees may satisfy withholding  obligations
as  provided  in this  paragraph.  When an  Optionee  incurs  tax  liability  in
connection  with an Option,  which tax  liability is subject to tax  withholding
under  applicable  tax laws, and the Optionee is obligated to pay the Company an
amount  required to be withheld  under  applicable  tax laws,  the  Optionee may
satisfy the withholding tax obligation by electing to have the Company  withhold
from the Shares to be issued upon exercise of the Option, if any, that number of
Shares  having a Fair Market Value equal to the amount  required to be withheld.
The Fair Market Value of the Shares to be withheld  shall be  determined  on the
date that the amount of tax to be withheld is to be determined.

     I. Time of Granting Options.  The date of grant of an Option shall, for all
purposes,  be the date on which the Board makes the determination  granting such
Option.  Notice  of the  determination  shall  be  given  to  each  Employee  or
Consultant  to whom an Option is so granted  within a reasonable  time after the
date of such grant.

     I. Amendment and Termination of the Plan.

     A.  Amendment  and  Termination.  The Board may at any time  amend,  alter,
suspend or  discontinue  the Plan, but no amendment,  alteration,  suspension or
discontinuation  shall be made which  would  impair  the rights of any  Optionee
under any grant theretofore made,  without his or her consent.  In addition,  to
the extent  necessary  and  desirable to comply with Section 422 of the Code (or
any other  applicable law or regulation,  including the requirements of the NASD
or an established stock exchange), the Company shall obtain shareholder approval
of any Plan amendment in such a manner and to such a degree as required.

     A. Effect of Amendment or Termination. Any such amendment or termination of
the Plan shall not affect Options  already granted and such Options shall remain
in full  force and effect as if this Plan had not been  amended  or  terminated,
unless  mutually  agreed  otherwise  between the Optionee  and the Board,  which
agreement must be in writing and signed by the Optionee and the Company.

     I. Conditions Upon Issuance of Shares.  Shares shall not be issued pursuant
to the exercise of an Option unless the exercise of such Option and the issuance
and  delivery of such Shares  pursuant  thereto  shall  comply with all relevant
provisions of law, including, without limitation, the Securities Act of 1933, as
amended, the Exchange Act, the rules and regulations promulgated thereunder, and
the requirements of any stock exchange upon which the Shares may then be listed,
and shall be further  subject to the  approval of counsel  for the Company  with
respect to such compliance.

     As a condition  to the  exercise of an Option,  the Company may require the
person  exercising  such Option to represent and warrant at the time of any such
exercise that the Shares are being purchased only for investment and without any
present  intention  to sell or  distribute  such  Shares  if, in the  opinion of
counsel  for  the  Company,  such a  representation  is  required  by any of the
aforementioned relevant provisions of law.

     I.  Reservation of Shares.  The Company, during the term of this Plan, will
at all  times  reserve  and keep  available  such  number  of Shares as shall be
sufficient to satisfy the requirements of the Plan.

     The inability of the Company to obtain  authority from any regulatory  body
having  jurisdiction,  which authority is deemed by the Company's  counsel to be
necessary to the lawful issuance and sale of any Shares hereunder, shall relieve
the  Company of any  liability  in respect of the  failure to issue or sell such
Shares as to which such requisite authority shall not have been obtained.

     I.  Option  Agreement.   Options  shall  be  evidenced  by  written  option
agreements in such form as the Board shall approve.

     I.  Shareholder  Approval.  Continuance  of the Plan  shall be  subject  to
approval by the  shareholders of the Company within twelve (12) months before or
after the date the Plan is adopted.  Such shareholder approval shall be obtained
in the degree and manner required under Applicable Laws.





<PAGE>




                                                              EXHIBIT 23.1


               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS


     We consent to the incorporation by reference in the Registration  Statement
on (Form S-8)  pertaining  to the 1993 Stock  Option Plan of Trimble  Navigation
Limited of our report dated  January 28, 1997 with  respect to the  consolidated
financial  statements and schedule of Trimble Navigation Limited included in its
Annual Report (Form 10-K) for the year ended December 31, 1996.






                                                /s/ERNST & YOUNG LLP



Palo Alto, California
May 28, 1997