<PAGE>   1
                                                                    EXHIBIT 4.1

                               SEAMED CORPORATION

                             1988 STOCK OPTION PLAN

     1.  INTRODUCTION:

         This Plan establishes the right of and procedures for SEAMED
Corporation (the "Company") to grant stock options to its key employees. The
Plan provides for the granting of two types of options, namely, (1)
Non-Qualified Stock Options and (2) Incentive Stock Options. This Plan sets
forth provisions applicable to both types of options, to Non-Qualified Options
only, and to Incentive Stock Options only.

     2.  PROVISIONS OF GENERAL APPLICATION:

         The provisions of this Section 2 apply to both Non-Qualified Options
and Incentive Stock Options granted by the Company.

         2.1      Objectives of the Plan:

         The purpose of this Plan is to encourage ownership of Common Stock of
the Company by key employees of the Company and any current or future
subsidiary. This Plan is intended to provide an incentive for maximum effort in
the successful operation of the Company and is expected to benefit the
shareholders by enabling the Company to attract and retain personnel of the best
available talent through the opportunity to share, by the proprietary interests
created by this Plan, in the increased value of the Company's shares to which
such personnel have contributed.

         2.2      Stock Reserved for this Plan:

         The stock reserved for issue upon the exercise of options granted under
this Plan will not exceed 680,000 Shares of the Common Stock of the Company (the
"Shares") which may be either authorized and unissued shares or issued shares
held in or hereafter acquired for the treasury of the Company. Shares subject to
any option under this Plan which is not exercised in full or Shares as to which
the right to purchase is forfeited through default or otherwise, shall remain
available for other options under this Plan provided that the aggregate number
of Shares subject to options under this Plan shall not exceed 680,000 shares of
said stock.

         2.3      Administration of this Plan:

         This Plan will be administered by the Board of Directors of the Company
(the "Board"). No member of the Board who is or may become eligible to receive
an option under this Plan shall 


<PAGE>   2

participate in the deliberations or actions of the Board in respect to this
Plan.

         A majority of the Board shall constitute a quorum, and acts of a
majority of the members present at any meeting at which a quorum is present, or
acts approved in writing by a majority of the Board, shall be deemed the acts of
the Board.

         The Board on consideration of recommendations of the President and of
other officers, if the Board shall deem the same appropriate, shall:

                  (a) Determine the number of shares subject to each option, the
terms thereof, the type of option to be granted, and direct the President, or
other officer in his absence, to issue such option;

                  (b) Prescribe rules and regulations from time to time for
administration of this Plan;

                  (c) Decide any questions arising as to the interpretation or
application of any provision of this Plan.

         Any action, decision, interpretation or determination by the Board with
respect to this Plan shall be final and binding upon any and all employees.

         2.4      Eligibility: Facts to be Considered in Granting Options:

         An option may be granted to any officer or key employee who, at the
time the option is granted, is a regular full-time employee of the Company or of
any subsidiary. In its determination of an employee to whom an option shall be
granted and the number of Shares to be covered by such option, the Board shall
take into account the duties of the employee, the present and potential
contributions of the employee to the success of the Company, the anticipated
number of years of service remaining before the attainment by the employee of
the age of retirement, and other factors deemed relevant by the Board in
connection with accomplishing the purpose of this Plan. An employee who has been
granted an option to purchase Shares of the Company, whether under this Plan or
otherwise, may, if the Board shall so determine be granted additional options.
As used in this Plan, the term "Optionee" shall refer to the holder of an option
granted hereunder.

         2.5      Vesting of Options:

         The Board shall have the authority to establish the time or times at
which the optioned Shares may be purchased and, whether all of the options may
be exercised at one time or in increments.
<PAGE>   3

         2.6 Rights of Optionee in Event of Merger, Consolidation, Tender
Offer, Takeover Bid, Sale of Assets, or Dissolution:

                  (a) Notwithstanding anything in this Plan to the contrary, the
Optionee may purchase the full amount of optioned Shares for which options have
been granted to the Optionee and for which the options have not been exercised
under the following conditions:

                         (1) The Optionee may conditionally purchase any or all
optioned Shares during the period commencing twenty-seven (27) days and ending
seven (7) days prior to the scheduled effective date of a merger or
consolidation (as such effective date may be delayed from time to time) wherein
the Company is not to be the surviving corporation, which merger or
consolidation is not between or among the Company and other corporations related
to or affiliated with the Company;

                         (2) The Optionee may conditionally purchase any or all
optioned Shares during the period commencing on the initial date of a tender
offer or takeover bid for the Shares (other than a tender offer by the Company)
subject to the Securities Exchange Act of 1934 and the rules promulgated
thereunder and ending on the day preceding the scheduled termination date of
acceptance of tenders of shares by the offeror under any such tender offer or
takeover bid (as such termination date may be extended by such offeror);

                         (3) The Optionee may conditionally purchase any or all
optioned Shares during the period commencing on the date the shareholders of the
Company approve a sale of substantially all the assets of the Company and ending
seven (7) days prior to the scheduled closing date of such sale (as such closing
date may be delayed from time to time).

                         (4) The Optionee may conditionally purchase any or all
optioned Shares during the period commencing on the date a majority of the
shareholders of the Company vote in favor of dissolving the Company and ending
thirty (30) days later but not in any event later than the day before the
Company files its Certificate of Dissolution,

                  (b) If the merger, consolidation, tender offer, takeover bid,
sale of assets, or dissolution, as the case may he and as described in
subsections (1) through (4) above, once commenced, is canceled or revoked, the
conditional purchase of Shares for which the option to purchase would not have
other otherwise been exercisable at the time of said cancellation or revocation,
but for the operation of this Section 2.6, shall be rescinded. With respect to
all other Shares conditionally purchased, the Optionee may rescind such purchase
at his option.
<PAGE>   4

                  (c) If the merger, consolidation, tender offer, takeover bid,
or sale of assets does occur or thirty (30) days passes after a majority of the
Company's shareholders vote in favor of dissolving the Company (or a Certificate
of Dissolution is filed) and the Optionee has not conditionally purchased all
optioned Shares, all unexercised options shall terminate on the effective,
termination or closing date, or thirty (30) days after the date of said vote
(but not later than the day before the Certificate of Dissolution is filed), as
the case may be.

                  (d) If the Company shall be the surviving corporation in any
merger or is a party to a merger or consolidation which is between or among the
Company and other corporations related to or affiliated with the Company, any
option granted hereunder shall pertain and apply to the securities to which a
holder of the number of Shares of Common Stock subject to the option would have
been entitled.

                  (e) Nothing herein shall allow the Optionee to purchase
optioned Shares, the options for which have expired.

         2.7      Terms and Expiration of Options:

         Each option granted under this Plan shall be in writing, shall be
subject to such amendment or modification from time to time as the Board shall
deem necessary or appropriate to comply with or take advantage of applicable
laws or regulations and shall contain provisions to the following effect,
together with such other provisions as the Board shall from time to time
approve:

                  (a) that, subject to the provisions of Section 2.7(b) below,
the option, as to the whole or any part thereof, may be exercised only by the
Optionee or his personal representative;

                  (b) that neither the whole nor any part of the option shall be
transferable by the Optionee or by operation of law otherwise than by the will
of, or by the laws of descent and distribution applicable to, a deceased
Optionee and that the option and any and all rights granted to the Optionee
thereunder and not theretofore effectively and completely exercised shall
automatically terminate and expire upon any sale, transfer or hypothecation or
any attempted sale, transfer or hypothecation of such rights or upon the
bankruptcy or insolvency of the Optionee or his or her estate;

                  (c) that subject to the foregoing provisions, an option may be
exercised at different times for portions of the total number of option Shares
for which the right to purchase or exercise shall have vested provided that such
portions are in multiples of one hundred (100) Shares;

                  (d) that the Optionee shall have no right to receive any
dividend on or to vote or exercise any right in respect to
<PAGE>   5

any Shares the certificate for which has not been issued to him or her;

                  (e) that the option shall expire at the earliest of the
following:

                           (1) The date specified in the option;

                           (2) A date specified in the option agreement but not
later than twelve (12) months after voluntary or involuntary termination of
Optionee's employment other than termination as described in Paragraph (3)
below;

                           (3) Upon the discharge of Optionee for misconduct,
willfully or recklessly harmful to the Company;

                           (4) Twelve (12) months after Optionee's death or
disability;

                           (5) In the event of a merger, consolidation, tender
offer, takeover bid, sale of assets or majority vote of the shareholders of the
Company in favor of dissolving (or the filing of a Certificate of Dissolution),
on the date specified in Section 2.6(c). However, if the merger, consolidation,
tender offer, takeover bid or sale of assets does not occur or if a Certificate
of Revocation of Voluntary Dissolution is filed within the thirty (30) days
after said majority vote, as the case may be, all options which are terminated
pursuant to this Subsection (e)(5) shall be reinstated as if no action with
respect to any of said events had been contemplated or taken by any party
thereto and all Optionees shall be returned to their position on the date of
termination; and

                  (f) that the terms of the option shall not be affected by any
change of the Optionee's duties or position so long as the Optionee shall
continue to be employed by the Company or a subsidiary.

         2.8      Notice of Intent to Exercise Option:

         The Optionee (or other person or persons, if any, entitled thereto
hereunder) desiring to exercise an option granted hereunder as to all or part of
the Shares covered thereby shall in writing notify the Company at its principal
office at Bothell, Washington, to that effect specifying the number of option
Shares to be purchased, and, if required by the Company, representing in form
satisfactory to the Company that the Shares are being purchased for investment
and not with a view to resale or distribution. With respect to any shares
conditionally purchased pursuant to Section 2.6(a) above and for which such
purchase has not been voluntarily or otherwise rescinded pursuant to Section
2.6(b), the Optionee shall be deemed to have given to the Company the notice of
exercise required by this Section 2.8 as of ten (10) days prior to the closing
or effective date of the 
<PAGE>   6

merger, consolidation, tender offer, takeover bid or sale of assets or as of the
twentieth (20th) day after a majority of the shareholders vote in favor of
dissolving the Company (or the tenth (10th) day before the filing of a
Certificate of Dissolution if it precedes said twentieth (20th) day), as the
case may be.

         2.9      Recapitalization:

         The aggregate number of Shares for which options may be granted
hereunder, the number of shares covered by each outstanding option, the price
per share thereof in each such option shall be proportionately adjusted for any
increase or decrease in the number of outstanding shares of Common Stock of the
Company resulting from a division or consolidation of shares or any other
increase or decrease in such shares effected without receipt of consideration by
the Company excluding any decrease resulting from the purchase of shares for the
treasury. If the adjustment would result in a fractional Share, the Optionee
shall be entitled to one (1) additional Share, provided that the total number of
Shares to be granted under this Plan shall not be increased above the equivalent
number of shares initially allocated to this Plan or subsequently approved by
the shareholders of the Company for issuance hereunder.

         2.10     Termination and Amendment of this Plan:

         The directors of the Company may at any time modify, amend or terminate
this Plan except with respect to options granted prior to such action, provided,
however, that no such amendment or modification shall increase the number of
Shares as to which options may be granted under this Plan or change the class of
employee to whom options may be granted under this Plan.

         2.11     Granting of Options:

         The granting of any option pursuant to this Plan shall be entirely in
the discretion of the Board and nothing herein contained shall be construed to
give any officer or employee any right to participate under this Plan or to
receive any option under it.

         The granting of an option pursuant to this Plan shall not constitute
any agreement or an understanding, express or implied, on the part of the
Company or a subsidiary to employ the Optionee for any specified period.

         2.12     Withdrawal:

         An Optionee may at any time elect in writing to abandon an option with
respect to the number of shares as to which the option shall not have been
exercised.
<PAGE>   7

         2.13     Government Regulations:

         This Plan and the granting and exercise of any option hereunder and the
obligations of the Company to sell and deliver shares under any such option
shall be subject to all applicable laws, rules and regulations, and to such
approvals by any governmental agencies as may be required. This Plan shall be
governed by the laws of the State of Washington.

         2.14     Shareholder Approval:

         This Plan shall be submitted to the shareholders for their approval
within twelve (12) months from the date hereof. The Company may grant options
prior to such approval which shall be conditioned upon subsequent shareholder
approval.

         2.15     Compliance with Securities Laws:

         The Board shall have the right to:

                  (a) require an Optionee to execute, as a condition of the
exercise of an option, a letter evidencing Optionee's intent to acquire the
Shares for investment and not with a view to the distribution thereof;

                  (b) place appropriate legends upon the certificate or 
certificates for the Shares; and

                  (c) take such other acts as it deems necessary in order to
cause the issuance of optioned Shares to comply with applicable provisions of
State and Federal Securities Laws.

         2.16     Method of Exercise of Option:

         Within ten (10) days after receipt of the Company of the notice
provided for in Section 2.8, but not later than the expiration date specified in
Section 2.7(e), the option shall be exercised as to the number of Shares
specified in the notice by payment to the Company of the amount specified in
either Section 3.2 or Section 4.5, as may be applicable. Payment of the purchase
price provided in the option shall be made in cash, in shares of the Company's
Common Stock owned by the Optionee, or in any combination of cash and shares of
the Company's Common Stock. Full or partial payment in Shares of the Company's
Common Stock shall be deemed to be the equivalent of payment in cash of the fair
market value of those shares. For purposes of the preceding sentence and this
Plan, "fair market value" is defined as the average, if any, of the closing
prices for the Common Stock as of 4:00 Eastern Time on the principal trading
exchange or national automated stock quotation system on which the Common Stock
is traded or quoted or, if there are no such closing prices or average, the
value of the Company's Common Stock as determined by the Board in good faith.
<PAGE>   8

         2.17     Substitutions and Assumptions:

         The Board shall have the right to substitute or assume options in
connection with mergers, reorganizations, separations or other "corporate
transactions" as that term is defined in and said substitutions and assumptions
are permitted by Section 425 of the Internal Revenue Code (the "Code") and the
regulations promulgated thereunder. The number of Shares reserved pursuant to
Section 2.2 may be increased by the corresponding number of options assumed and,
in the case of a substitution, by the net increase in the number of Shares
subject to options before and after the substitution.

         2.18     Proceeds from Sale of Stock:

         Proceeds of the purchase of optioned Shares by an Optionee shall be for
the general business purposes of the Company.

         2.19     Terminal Date of Plan:

         This Plan shall not extend beyond April 11, 1998.

     3.  PROVISIONS APPLICABLE SOLELY TO NON-QUALIFIED STOCK OPTIONS:

         In addition to the provisions of Section 2 above, the following
paragraphs shall apply to any options granted under this Plan which are not
Incentive Stock Options.

         3.1      Option Price:

         The option or purchase price of each Share optioned under this Plan
shall be determined by the Board at the time of the action for the granting of
the option.

         3.2      Method of Exercise of Option:

         The amount to be paid by the Optionee upon exercise of a Non-Qualified
Option shall be the full purchase price thereof provided in the option, together
with the amount of federal, state or local taxes of any kind required to be
withheld by the Company. An Optionee may elect to pay his withholding taxes by
having the Company withhold shares of Company common stock having a value equal
to the amount required to be withheld. The value of the shares to be withheld is
deemed to equal the fair market value of the shares on the day the option is
exercised. An election by an Optionee to have shares withheld for this purpose
will be subject to the following restrictions:

         (a) if an Optionee has received multiple option grants, a separate
election must be made for each grant;
<PAGE>   9

         (b) the election must be made prior to the day the option is exercised;

         (c) the election will be irrevocable;

         (d) the election will be subject to the disapproval of the Board;

         (e) if the Optionee is an officer of the Company within the meaning of
Section 16 of the Securities Exchange Act of 1934 ("Section 16"), the election
may not be made within six months following the grant of the option; and

         (f) if the Optionee is an officer of the Company within the meaning of
Section 16, the election must be made either six months prior to the day the
option is exercised or in the ten-day "window period" beginning on the third day
following the release of the Company's quarterly or annual summary statement of
sales and earnings.

     4.  PROVISIONS APPLICABLE SOLELY TO INCENTIVE STOCK OPTIONS:

         In addition to the provisions of Section 3 above, the following
paragraphs shall apply to any options granted under this Plan which are
Incentive Stock Options.

         4.1      Conformance with Internal Revenue Code:

         Options granted under this Plan which are "Incentive Stock Options"
shall conform to, be governed by and interpreted in accordance with Section 422A
of the Code and any regulations promulgated thereunder as well as any amendments
to the Code and Regulations.

         4.2      Option Price:

         The option or purchase price of each Share optioned under the Incentive
Stock Option provisions of this Plan shall be determined by the Board at the
time of the action for the granting of the option but shall not, in any event,
be less than the fair market value of the Company's common stock on the date of
grant.

         4.3      Limitation on Vesting of Incentive Stock Options:

         The aggregate fair market value of the option Shares (determined on the
date of grant) with respect to which an employee's right to exercise vests in
any one calendar year (under this Plan or any other plan of the Company which
authorizes Incentive Stock Options) shall not exceed $100,000.
<PAGE>   10

         4.4      Limitation on Grants to Substantial Shareholders:

         An employee may not, immediately prior to the grant of an Incentive
Stock option hereunder, own stock in the Company representing more than ten
percent (10%) of the voting power of all classes of stock of the Company unless
the per share option price specified by the Board for the Incentive Stock
Options granted such an employee is at least one hundred ten percent (110%) of
the fair market value of the Company's stock on the date of grant and such
option, by its terms, is not exercisable after the expiration of five (5) years
from the date such option is granted.

         4.5      Method of Exercise of Option:

         The amount to be paid by the optionee upon exercise of an Incentive
Stock Option shall be the full purchase price thereof provided in the option.