<PAGE>   1
                                                                  EXHIBIT 10.2

                         COMMERCIAL SECURITY AGREEMENT

<TABLE>
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PRINCIPAL         LOAN DATE       MATURITY     LOAN NO.     CALL     COLLATERAL   ACCOUNT    OFFICER    INITIAL          
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<S>               <C>            <C>           <C>          <C>      <C>          <C>        <C>        <C>
$4,000,000.00     12-05-1996     02-05-1997    1-3895-6     0400       AR/IN                   MHD         S
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          REFERENCES IN THE SHADED AREA ARE FOR LENDER'S USE ONLY AND DO NOT LIMIT THE APPLICABILITY OF THIS DOCUMENT
                                                   TO ANY PARTICULAR LOAN OR ITEM
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</TABLE>

BORROWER: SEAMED CORPORATION (TIN: 91-1002092) LENDER: PACIFIC NORTHWEST BANK  
          14500 NE 87TH STREET                         BELLEVUE FINANCIAL CENTER
          REDMOND, WA  98052-3431                      11100 NE 8TH
                                                       BELLEVUE, WA  98004
================================================================================


THIS COMMERCIAL SECURITY AGREEMENT IS ENTERED INTO BETWEEN SEAMED CORPORATION
(REFERRED TO BELOW AS "GRANTOR"); AND PACIFIC NORTHWEST BANK (REFERRED TO BELOW
AS "LENDER").  FOR VALUABLE CONSIDERATION, GRANTOR GRANTS TO LENDER A SECURITY
INTEREST IN THE COLLATERAL TO SECURE THE INDEBTEDNESS AND AGREES THAT LENDER
SHALL HAVE THE RIGHTS STATED IN THIS AGREEMENT WITH RESPECT TO THE COLLATERAL,
IN ADDITION TO ALL OTHER RIGHTS WHICH LENDER MAY HAVE BY LAW.

DEFINITIONS.  The following words shall have the following meanings when used
in this Agreement.  Terms not otherwise defined in this Agreement shall have
the meanings attributed to such terms in the Uniform Commercial Code.  All
references to dollar amounts shall mean amounts in lawful money of the United
States of America.

         AGREEMENT.  The word "Agreement" means this Commercial Security
         Agreement, as this Commercial Security Agreement may be amended or
         modified from time to time, together with all exhibits and schedules
         attached to this Commercial Security Agreement from time to time.

         COLLATERAL.  The word "Collateral" means the following described
         property of Grantor, whether now owned or hereafter acquired, whether
         now existing or hereafter arising, and whenever located:

                 ALL INVENTORY, ACCOUNTS AND GENERAL INTANGIBLES

         In addition, the word "Collateral" includes all the following, whether
         now owned or hereafter acquired, whether now existing or hereafter
         arising, and wherever located:

                 (a)      All attachments, accessions, accessories, tools,
                 parts, supplies, increases, and additions to and all
                 replacements of and substitutions for any property described
                 above.

                 (b)      All products and produce of any of the property
                 described in this Collateral section.

                 (c)      All accounts, general intangibles, instruments,
                 rents, monies, payments, and all other rights, arising out of
                 a sale, lease or other disposition of any of the property
                 described in this Collateral section.

                 (d)      All proceeds (including insurance proceeds) from the
                 sale, destruction, loss, or other disposition of any of the
                 property described in this Collateral section.

                 (e)      All records and data relating to any of the property
                 described in this Collateral section, whether in the form of a
                 writing, photograph, microfilm, microfiche, or electronic
                 media, together with all of Grantor's right, title, and
                 interest in and to all computer software required to utilize,
                 create, maintain, and process any such records or data on
                 electronic media.

         EVENT OF DEFAULT.  The words "Event of Default" mean and include
         without limitation any of the Events of Default set forth below in the
         section titled "Events of Default."





                                      -1-
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         GRANTOR.  The word "Grantor" means SEAMED CORPORATION, its successors
         and assigns.

         GUARANTOR.  The word "Guarantor" means and includes without limitation
         each and all of the guarantors, sureties, and accommodation parties in
         connection with the indebtedness.

         INDEBTEDNESS.  The word "indebtedness means the indebtedness evidenced
         by the Note, including all principal and interest, together with all
         other indebtedness and costs and expenses for which Grantor is
         responsible under this Agreement or under any of the Related
         Documents.

         LENDER.  The word "Lender" means Pacific Northwest Bank, its
         successors and assigns.

         NOTE.  The word "Note" means the note or credit agreement dated
         December 5, 1996, in the principal amount of $4,000,000.00 from SEAMED
         CORPORATION to Lender, together with all renewals of, extensions of,
         modifications of, refinancing of, consolidations of and substitutions
         for the note or credit agreement.

         RELATED DOCUMENTS.  The words "Related Documents" mean and include
         without limitation all promissory notes, credit agreements, loan
         agreements, environmental agreements, guaranties, security agreements,
         mortgages, deeds of trust, and all other instruments, agreements and
         documents, whether now or hereafter existing, executed in connection
         with the indebtedness.

RIGHT OF SETOFF.  Grantor hereby grants Lender a contractual possessory
security interest in, and hereby assigns, conveys, delivers, pledges, and
transfers all of Grantor's right, title and interest in and to Grantor's
accounts with Lender (whether checking, savings, or some other account),
including all accounts held jointly with someone else and all accounts Grantor
may open in the future, excluding, however, all IRA and Keogh accounts, and all
trust accounts for which the grant of a security interest would be prohibited
by law.  Grantor authorizes Lender, to the extent permitted by applicable law,
to charge or setoff all indebtedness against any and all such accounts.

OBLIGATIONS OF GRANTOR.  Grantor warrants and covenants to Lender as follows:

         ORGANIZATION.  Grantor is a corporation which is duly organized,
         validly existing, and in good standing under the laws of the State of
         Washington.  Grantor has its chief executive office at 14500 NE 87TH
         STREET, REDMOND, WA 98052-3431.  Grantor will notify Lender of any
         change in the location of Grantor's chief executive office.

         AUTHORIZATION.  The execution, delivery, and performance of this
         Agreement by Grantor have been duly authorized by all necessary action
         by Grantor and do not conflict with, result in a violation of, or
         constitute a default under (a) any provision of its articles of
         incorporation or organization, or bylaws, or any agreement or other
         instrument binding upon Grantor or (b) any law, governmental
         regulation, court decree, or order applicable to Grantor.

         PERFECTION OF SECURITY INTEREST.  Grantor agrees to execute such
         financing statements and to take whatever other actions are requested
         by Lender to perfect and continue Lender's security interest in the
         Collateral.  Upon request of Lender, Grantor will deliver to Lender
         any and all of the documents evidencing or constituting the
         Collateral, and Grantor will note Lender's interest upon any and all
         chattel paper if not delivered to Lender for possession by Lender.
         Grantor hereby appoints Lender as its irrevocable attorney-in-fact for
         the purpose of executing any documents necessary to perfect or to
         continue the security interest granted in this Agreement.  Lender may
         at any time, and without further authorization from Grantor, file a
         carbon, photographic or other reproduction of any financing statement
         or of this Agreement for use as a financing statement.  Grantor will
         reimburse Lender for all expenses for the perfection and the
         continuation of the perfection of Lender's security interest in the
         Collateral.  Grantor promptly will notify Lender before any change in
         Grantor's name including any change to the assumed business names of
         Grantor.  This is a






<PAGE>   3
         continuing Security Agreement and will continue in effect even though
         all or any part of the indebtedness is paid in full and even though
         for a period of time Grantor may not be indebted to Lender.

         NO VIOLATION.  The execution and delivery of this Agreement will not
         violate any law or agreement governing Grantor or to which Grantor is
         a party, and its certificate or articles of incorporation and bylaws
         do not prohibit any term or condition of this Agreement.

         ENFORCEABILITY OF COLLATERAL.  To the extent the Collateral consists
         of accounts, chattel paper, or general intangibles, the Collateral is
         enforceable in accordance with its terms, is genuine, and complies
         with applicable laws concerning form, content and manner of
         preparation and execution, and all persons appearing to be obligated
         on the Collateral have authority and capacity to contract and are in
         fact obligated as they appear to be on the Collateral.  At the time
         any account becomes subject to a security interest in favor of Lender,
         the account shall be a good and valid account representing an
         undisputed, bona fide indebtedness incurred by the account debtor, for
         merchandise held subject to delivery instructions or theretofore
         shipped or delivered pursuant to a contract of sale, or for services
         theretofore performed by Grantor with or for the account debtor; there
         shall be no setoffs or counterclaims against any such account; and no
         agreement under which any deductions or discounts may be claimed shall
         have been made with the account debtor except those disclosed to
         Lender in writing.

         LOCATION OF THE COLLATERAL.  Grantor, upon request of Lender, will
         deliver to Lender in form satisfactory to Lender a schedule of real
         properties and Collateral locations relating to Grantor's operations,
         including without limitation the following:  (a) all real property
         owned or being purchased by Grantor; (b) all real property being
         rented or leased by Grantor; (c) all storage facilities owned, rented,
         leased, or being used by Grantor; and (d) all other properties where
         Collateral is or may be located.  Except in the ordinary course of its
         business, Grantor shall not remove the Collateral from its existing
         locations without the prior written consent of Lender.

         REMOVAL OF COLLATERAL.  Grantor shall keep the Collateral (or to the
         extent the Collateral consists of intangible property such as
         accounts, the records concerning the Collateral) at Grantor's address
         shown above, or at such other locations as are acceptable to Lender.
         Except in the ordinary course of its business, including the sales of
         inventory, Grantor shall not remove the Collateral from its existing
         locations without the prior written consent of Lender.  To the extent
         that the Collateral consists of vehicles, or other titled property,
         Grantor shall not take or permit any action which would require
         application for certificates of title for the vehicles outside the
         State of Washington, without the prior written consent of Lender.

         TRANSACTIONS INVOLVING COLLATERAL.  Except for inventory sold or
         accounts collected in the ordinary course of Grantor's business,
         Grantor shall not sell, offer to sell, or otherwise transfer or
         dispose of the Collateral.  While Grantor is not in default under this
         Agreement, Grantor may sell inventory, but only in the ordinary course
         of its business and only to buyers who qualify as a buyer in the
         ordinary course of business.  A sale in the ordinary course of
         Grantor's business does not include a transfer in partial or total
         satisfaction of a debt or any bulk sale.  Grantor shall not pledge,
         mortgage, encumber or otherwise permit the Collateral to be subject to
         any lien, security interest, encumbrance, or charge, other than the
         security interest provided for in this Agreement, without the prior
         written consent of Lender.  This includes security interests even if
         junior in right to the security interests granted under this
         Agreement.  Unless waived by Lender, all proceeds from any disposition
         of the Collateral (for whatever reason) shall be held in trust for
         Lender and shall not be commingled with any other funds; provided
         however, this requirement shall not constitute consent by Lender to
         any sale or other disposition.  Upon receipt, Grantor shall
         immediately deliver any such proceeds to Lender.

         TITLE.  Grantor represents and warrants to Lender that it holds good
         and marketable title to the Collateral, free and clear of all liens
         and encumbrances except for the lien of this Agreement.  No financing
         statement covering any of the Collateral is on file in any public
         office other than those which reflect the security interest created by
         this Agreement or to which Lender has specifically consented.  Grantor
         shall defend Lender's rights in the Collateral against the claims and
         demands of all other persons.






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         COLLATERAL SCHEDULES AND LOCATIONS.  As often as Lender shall require,
         and insofar as the Collateral consists of accounts and general
         intangibles, Grantor shall deliver to Lender schedules of such
         Collateral, including such information as Lender may require,
         including without limitation names and addresses of account debtors
         and agings of accounts and general intangibles.  Insofar as the
         Collateral consists of inventory, Grantor shall deliver to Lender, as
         often as Lender shall require, such lists, descriptions, and
         designations of such Collateral as Lender may require to identify the
         nature, extent, and location of such Collateral.  Such information
         shall be submitted for Grantor and each of its subsidiaries or related
         companies.

         MAINTENANCE AND INSPECTION OF COLLATERAL.  Grantor shall maintain all
         tangible Collateral in good condition and repair.  Grantor will not
         commit or permit damage to or destruction of the Collateral or any
         part of the Collateral.  Lender and its designated representatives and
         agents shall have the right at all reasonable times to examine,
         inspect, and audit the Collateral wherever located.  Grantor shall
         immediately notify Lender of all cases involving the return,
         rejection, repossession, loss or damage of or to any Collateral; of
         any request for credit or adjustment or of any other dispute arising
         with respect to the Collateral; and generally of all happenings and
         events affecting the Collateral or the value or the amount of the
         Collateral.

         TAXES, ASSESSMENTS AND LIENS.  Grantor will pay when due all taxes,
         assessments and liens upon the Collateral, its use or operation, upon
         this Agreement, upon any promissory note or notes evidencing the
         indebtedness, or upon any of the other Related Documents.  Grantor may
         withhold any such payment or may elect to contest any lien if Grantor
         is in good faith conducting an appropriate proceeding to contest the
         obligation to pay and so long as Lender's interest in the Collateral
         is not jeopardized in Lender's sole opinion.  If the Collateral is
         subjected to a lien which is not discharged within fifteen (15) days,
         Grantor shall deposit with Lender cash, a sufficient corporate surety
         bond or other security satisfactory to Lender in an amount adequate to
         provide for the discharge of the lien plus any interest, costs,
         attorneys' fees or other charges that could accrue as a result of
         foreclosure or sale of the Collateral.  In any contest Grantor shall
         defend itself and Lender and shall satisfy any final adverse judgment
         before enforcement against the Collateral.  Grantor shall name Lender
         as an additional obligee under any surety bond furnished in the
         contest proceedings.

         COMPLIANCE WITH GOVERNMENTAL REQUIREMENTS.  Grantor shall comply
         promptly with all laws, ordinances, rules and regulations of all
         governmental authorities, now or hereafter in effect, applicable to
         the ownership, production, disposition, or use of the Collateral.
         Grantor may contest in good faith any such law, ordinance or
         regulation and withhold compliance during any proceeding, including
         appropriate appeals, so long as Lender's interest in the Collateral,
         in Lender's opinion, is not jeopardized.

         HAZARDOUS SUBSTANCES.  Grantor represents and warrants that the
         Collateral never has been, and never will be so long as this Agreement
         remains a lien on the Collateral, used for the generation,
         manufacture, storage, transportation, treatment, disposal, release or
         threatened release of any hazardous waste or substance, as those terms
         are defined in the Comprehensive Environmental Response, Compensation,
         and Liability Act of 1980, as amended, 42 U.S.C. Section 9601, et seq.
         ("CERCLA"), the Superfund Amendments and Reathorization Act of 1986,
         Pub. L. No. 99-499 ("SARA"), the Hazardous Materials Transportation
         Act, 49 U.S.C. Section 1801, et. seq., the Resource Conservation and
         Recovery Act, 42 U.S.C. Section 6901, et seq., or other applicable
         state or Federal laws, rules, or regulations adopted pursuant to any
         of the foregoing.  The terms "hazardous waste" and "hazardous
         substance" shall also include, without limitation, petroleum and
         petroleum by-products or any fraction thereof and asbestos.  The
         representations and warranties contained herein are based on Grantor's
         due diligence in investigating the Collateral for hazardous wastes and
         substances.  Grantor hereby (a) releases and waives any future claims
         against Lender for indemnity or contribution in the event Grantor
         becomes liable for cleanup or other costs under any such laws, and (b)
         agrees to indemnify and hold harmless Lender against any and all
         claims and losses resulting from a breach of this provision of this
         Agreement.  This obligation to indemnify shall survive the payment of
         the indebtedness and the satisfaction of this Agreement.






<PAGE>   5
         MAINTENANCE OF CASUALTY INSURANCE.  Grantor shall procure and maintain
         all risks insurance, including without limitation fire, theft and
         liability coverage together with such other insurance as Lender may
         require with respect to the Collateral, in form, amounts, coverages
         and basis reasonably acceptable to Lender and issued by a company or
         companies reasonably acceptable to Lender.  Grantor, upon request of
         Lender, will deliver to Lender from time to time the policies or
         certificates of insurance in form satisfactory to Lender, including
         stipulations that coverages will not be cancelled or diminished
         without at least thirty (30) days' prior written notice to Lender and
         not including any disclaimer of the insurer's liability for failure to
         give such a notice.  Each insurance policy also shall include an
         endorsement providing that coverage in favor of Lender will not be
         impaired in any way by any act, omission or default of Grantor or any
         other person.  In connection with all policies covering assets in
         which Lender holds or is offered a security interest, Grantor will
         provide Lender with such loss payable or other endorsements as Lender
         may require.  If Grantor at any time fails to obtain or maintain any
         insurance as required under this Agreement, Lender may (but shall not
         be obligated to) obtain such insurance as Lender deems appropriate,
         including if it so chooses "single interest insurance," which will
         cover only Lender's interest in the Collateral.

         APPLICATION OF INSURANCE PROCEEDS.  Grantor shall promptly notify
         Lender of any loss or damage to the Collateral.  Lender may make proof
         of loss if Grantor fails to do so within fifteen (15) days of the
         casualty.  All proceeds of any insurance on the Collateral, including
         accrued proceeds thereon, shall be held by Lender as part of the
         Collateral.  If Lender consents to repair or replacement of the
         damaged or destroyed Collateral, Lender shall, upon satisfactory proof
         of expenditure, pay or reimburse Grantor from the proceeds for the
         reasonable cost of repair or restoration.  If Lender does not consent
         to repair or replacement of the Collateral, Lender shall retain a
         sufficient amount of the proceeds to pay all of the indebtedness, and
         shall pay the balance to Grantor.  Any proceeds which have not been
         disbursed within six (6) months after their receipt and which Grantor
         has not committed to the repair or restoration of the Collateral shall
         be used to prepay the indebtedness.

         INSURANCE RESERVES.  Lender may require Grantor to maintain with
         Lender reserves for payment of insurance premiums, which reserves
         shall be created by monthly payments from Grantor of a sum estimated
         by Lender to be sufficient to produce, at least fifteen (15) days
         before the premium due date, amounts at least equal to the insurance
         premiums to be paid.  If fifteen (15) days before payment is due, the
         reserve funds are insufficient, Grantor shall upon demand pay any
         deficiency to Lender.  The reserve funds shall be held by Lender as a
         general deposit and shall constitute a non-interest-bearing account
         which Lender may satisfy by payment of the insurance premiums required
         to be paid by Grantor as they become due.  Lender does not hold the
         reserve funds in trust for Grantor, and Lender is not the agent of
         Grantor for payment of the insurance premiums required to be paid by
         Grantor.  The responsibility for the payment of premiums shall remain
         Grantor's sole responsibility.

         INSURANCE REPORTS.  Grantor, upon request of Lender, shall furnish to
         Lender reports on each existing policy of insurance showing such
         information as Lender may reasonably request including the following:
         (a) the name of the insurer; (b) the risks insured; (c) the amount of
         the policy; (d) the property insured; (e) the then current value on
         the basis of which insurance has been obtained and the manner of
         determining that value; and (f) the expiration date of the policy.  In
         addition, Grantor shall upon request by Lender (however not more often
         than annually) have an independent appraiser satisfactory to Lender
         determine, as applicable, the cash value or replacement cost of the
         Collateral.

GRANTOR'S RIGHT TO POSSESSION AND TO COLLECT ACCOUNTS.  Until default and
except as otherwise provided below with respect to accounts, Grantor may have
possession of the tangible personal property and beneficial use of all the
Collateral and may use it in any lawful manner not inconsistent with this
Agreement or the Related Documents, provided that Grantor's right to possession
and beneficial use shall not apply to any Collateral where possession of the
Collateral by Lender is required by law to perfect Lender's security interest
in such Collateral.  Until otherwise notified by Lender, Grantor may collect
any of the Collateral consisting of accounts.  At any time and even though no
Event of Default exists, Lender may exercise its rights to collect the accounts
and to notify account debtors to make payments directly to Lender for
application to the Indebtedness.  If






<PAGE>   6
Lender at any time has possession of any Collateral, whether before or after an
Event of Default, Lender shall be deemed to have exercised reasonable care in
the custody and preservation of the Collateral if Lender takes such action for
that purpose as Grantor shall request or as Lender, in Lender's sole
discretion, shall deem appropriate under the circumstances, but failure to
honor any request by Grantor shall not of itself be deemed to be a failure to
exercise reasonable care.  Lender shall not be required to take any steps
necessary to preserve any rights in the Collateral against prior parties, nor
to protect, preserve or maintain any security interest given to secure the
indebtedness.

EXPENDITURES BY LENDER.  If not discharged or paid when due, Lender may (but
shall not be obligated to) discharge or pay any amounts required to be
discharged or paid by Grantor under this Agreement, including without
limitation all taxes, liens, security interests, encumbrances, and other
claims, at any time levied or placed on the Collateral.  Lender also may (but
shall not be obligated to) pay all costs for insuring, maintaining and
preserving the Collateral.  All such expenditures incurred or paid by Lender
for such purposes will then bear interest at the rate charged under the Note
from the date incurred or paid by Lender to the date of repayment by Grantor.
All such expenses shall become a part of the indebtedness and, at Lender's
option, will (a) be payable on demand, (b) be added to the balance of the Note
and be apportioned among and be payable with any installment payments to become
due during either (i) the term of any applicable insurance policy or (ii) the
remaining term of the Note, or (c) be treated as a balloon payment which will
be due and payable at the Note's maturity.  This Agreement also will secure
payment of these amounts.  Such right shall be in addition to all other rights
and remedies to which Lender may be entitled upon the occurrence of an Event of
Default.

EVENTS OF DEFAULT.  Each of the following shall constitute an Event of Default
under this Agreement:

         DEFAULT ON INDEBTEDNESS.  Failure of Grantor to make any payment when
         due on the indebtedness.

         OTHER DEFAULTS.  Failure of Grantor to comply with or to perform any
         other term, obligation, covenant or condition contained in this
         Agreement or in any of the Related Documents or in any other agreement
         between Lender and Grantor.

         FALSE STATEMENTS.  Any warranty, representation or statement made or
         furnished to Lender by or on behalf of Grantor under this Agreement,
         the Note or the Related Documents is false or misleading in any
         material respect, either now or at the time made or furnished.

         DEFECTIVE COLLATERALIZATION.  This Agreement or any of the Related
         Documents ceases to be in full force and effect (including failure of
         any collateral documents to create a valid and perfected security
         interest or lien) at any time and for any reason.

         INSOLVENCY.  The dissolution or termination of Grantor's existence as
         a going business, the insolvency of Grantor, the appointment of a
         receiver for any part of Grantor's property, any assignment for the
         benefit of creditors, any type of creditor workout, or the
         commencement of any proceeding under any bankruptcy or insolvency laws
         by or against Grantor.

         CREDITOR OR FORFEITURE PROCEEDINGS.  Commencement of foreclosure or
         forfeiture proceedings, whether by judicial proceeding, self-help,
         repossession or any other method, by any creditor of Grantor or by any
         governmental agency against the Collateral or any other collateral
         securing the indebtedness.  This includes a garnishment of any of
         Grantor's deposit accounts with Lender.

         EVENTS AFFECTING GUARANTOR.  Any of the preceding events occurs with
         respect to any Guarantor of any of the indebtedness or such Guarantor
         dies or becomes incompetent.

         ADVERSE CHANGE.  A material adverse change occurs in Grantor's
         financial condition, or Lender believes the prospect of payment or
         performance of the indebtedness is impaired.

         INSECURITY.  Lender, in good faith, deems itself insecure.





<PAGE>   7
RIGHTS AND REMEDIES ON DEFAULT.  If an Event of Default occurs under this
Agreement, at any time thereafter, Lender shall have all the rights of a
secured party under the Washington Uniform Commercial Code.  In addition and
without limitation, Lender may exercise any one or more of the following rights
and remedies:

         ACCELERATE INDEBTEDNESS.  Lender may declare the entire indebtedness,
         including any prepayment penalty which Grantor would be required to
         pay, immediately due and payable, without notice.

         ASSEMBLE COLLATERAL.  Lender may require Grantor to deliver to Lender
         all or any portion of the Collateral and any and all certificates of
         title and other documents relating to the Collateral.  Lender may
         require Grantor to assemble the Collateral and make it available to
         Lender at a place to be designated by Lender.  Lender also shall have
         full power to enter upon the property of Grantor to take possession of
         and remove the Collateral.  If the Collateral contains other goods not
         covered by this Agreement at the time of repossession, Grantor agrees
         Lender may take such other goods, provided that Lender makes
         reasonable efforts to return them to Grantor after repossession.

         SELL THE COLLATERAL.  Lender shall have full power to sell, lease,
         transfer, or otherwise deal with the Collateral or proceeds thereof in
         its own name or that of Grantor.  Lender may sell the Collateral at
         public auction or private sale.  Unless the Collateral threatens to
         decline speedily in value or is of a type customarily sold on a
         recognized market, Lender will give Grantor reasonable notice of the
         time after which any private sale or any other intended disposition of
         the Collateral is to be made.  The requirements of reasonable notice
         shall be met if such notice is given at least ten (10) days before the
         time of the sale or disposition.  All expenses relating to the
         disposition of the Collateral, including without limitation the
         expenses of retaking, holding, insuring, preparing for sale and
         selling the Collateral, shall become a part of the indebtedness
         secured by this Agreement and shall be payable on demand, with
         interest at the Note rate from date of expenditure until repaid.

         APPOINT RECEIVER.  To the extent permitted by applicable law, Lender
         shall have the following rights and remedies regarding the appointment
         of a receiver:  (a) Lender may have a receiver appointed as a matter
         of right, (b) the receiver may be an employee of Lender and may serve
         without bond, and (c) all fees of the receiver and his or her attorney
         shall become part of the indebtedness secured by this Agreement and
         shall be payable on demand, with interest at the Note rate from date
         of expenditure until repaid.

         COLLECT REVENUES, APPLY ACCOUNTS.  Lender, either itself or through a
         receiver, may collect the payments, rents, income, and revenues from
         the Collateral.  Lender may at any time in its discretion transfer any
         Collateral into its own name or that of its nominee and receive the
         payments, rents, income, and revenues therefrom and hold the same as
         security for the indebtedness or apply it to payment of the
         indebtedness in such order of preference as Lender may determine.
         Insofar as the Collateral consists of accounts, general intangibles,
         insurance policies, instruments, chattel paper, choses in action, or
         similar property, Lender may demand, collect receipt for, settle,
         compromise, adjust, sue for, foreclose, or realize on the Collateral
         as Lender may determine, whether or not indebtedness or Collateral is
         then due.  For these purposes, Lender may, on behalf of and in the
         name of Grantor, receive, open and dispose of mail addressed to
         Grantor; change any address to which mail and payments are to be sent;
         and endorse notes, checks, drafts, money orders, documents of title,
         instruments and items pertaining to payment, shipment, or storage of
         any Collateral.  To facilitate collection, Lender may notify account
         debtors and obligors on any Collateral to make payments directly to
         Lender.

         OBTAIN DEFICIENCY.  If Lender chooses to sell any or all of the
         Collateral, Lender may obtain a judgment against Grantor for any
         deficiency remaining on the indebtedness due to Lender after
         application of all amounts received from the exercise of the rights
         provided in this Agreement.  Grantor shall be liable for a deficiency
         even if the transaction described in this subsection is a sale of
         accounts or chattel paper.

         OTHER RIGHTS AND REMEDIES.  Lender shall have all the rights and
         remedies of a secured creditor under the provisions of the Uniform
         Commercial Code, as may be amended from time to time.  In addition,
         Lender





<PAGE>   8
         shall have and may exercise any or all other rights and remedies it
         may have available at law, in equity, or otherwise.

         CUMULATIVE REMEDIES.  All of Lender's rights and remedies, whether
         evidenced by this Agreement or the Related Documents or by any other
         writing, shall be cumulative and may be exercised singularly or
         concurrently.  Election by Lender to pursue any remedy shall not
         exclude pursuit of any other remedy, and an election to make
         expenditures or to take action to perform an obligation of Grantor
         under this Agreement, after Grantor's failure to perform, shall not
         affect Lender's right to declare a default and to exercise its
         remedies.

MISCELLANEOUS PROVISIONS.  The following miscellaneous provisions are part of
this Agreement:

         AMENDMENTS.  This Agreement, together with any Related Documents,
         constitutes the entire understanding and agreement of the parties as
         to the matters set forth in this Agreement.  No alteration of or
         amendment to this Agreement shall be effective unless given in writing
         and signed by the party or parties sought to be charged or bound by
         the alteration or amendment.

         APPLICABLE LAW.  This Agreement has been delivered to Lender and
         accepted by Lender in the State of Washington.  If there is a lawsuit,
         Grantor agrees upon Lender's request to submit to the jurisdiction of
         the courts of the State of Washington.  This Agreement shall be
         governed by and construed in accordance with the laws of the State of
         Washington.

         ATTORNEY'S FEES; EXPENSES.  Grantor agrees to pay upon demand all of
         Lender's costs and expenses, including attorneys' fees and Lender's
         legal expenses, incurred in connection with the enforcement of this
         Agreement.  Lender may pay someone else to help enforce this
         Agreement, and Grantor shall pay the costs and expenses of such
         enforcement.  Costs and expenses include Lender's attorneys' fees and
         legal expenses whether or not there is a lawsuit, including attorneys'
         fees and legal expenses for bankruptcy proceedings (and including
         efforts to modify or vacate any automatic stay or injunction),
         appeals, and any anticipated post-judgment collection services.
         Grantor also shall pay all court costs and such additional fees as may
         be directed by the court.

         CAPTION HEADINGS.  Caption headings in this Agreement are for
         convenience purposes only and are not to be used to interpret or
         define the provisions of this Agreement.

         MULTIPLE PARTIES; CORPORATE AUTHORITY.  All obligations of Grantor
         under this Agreement shall be joint and several, and all references to
         Grantor shall mean each and every Grantor.  This means that each of
         the Borrowers signing below is responsible for all obligations in this
         Agreement.

         NOTICES.  All notices required to be given under this Agreement shall
         be given in writing, may be sent by telefacsimile, and shall be
         effective when actually delivered or when deposited with a nationally
         recognized overnight courier or deposited in the United States mail,
         first class, postage prepaid, addressed to the party to whom the
         notice is to be given at the address shown above.  Any party may
         change its address for notices under this Agreement by giving formal
         written notice to the other parties, specifying that the purpose of
         the notice is to change the party's address.  To the extent permitted
         by applicable law, if there is more than one Grantor, notice to any
         Grantor will constitute notice to all Grantors.  For notice purposes,
         Grantor will keep Lender informed at all times of Grantor's current
         address(es).

         POWER OF ATTORNEY.  Grantor hereby appoints Lender as its true and
         lawful attorney-in-fact, irrevocably, with full power of substitution
         to do the following:  (a) to demand, collect, receive, receipt for,
         sue and recover all sums of money or other property which may now or
         hereafter become due, owing or payable from the Collateral; (b) to
         execute, sign and endorse any and all claims, instruments, receipts,
         checks, drafts or warrants issued in payment for the Collateral; (c)
         to settle or compromise any and all claims arising under the
         Collateral, and, in the place and stead of Grantor, to execute and
         deliver its release and settlement for the claim; and (d) to file any
         claim or claims or to take any action or institute or take part in





<PAGE>   9
         any proceedings, either in its own name or in the name of Grantor, or
         otherwise, which in the discretion of Lender may seem to be necessary
         or advisable.  This power is given as security for the indebtedness,
         and the authority hereby conferred is and shall be irrevocable and
         shall remain in full force and effect until renounced by Lender.

         PREFERENCE PAYMENTS.  Any monies Lender pays because of an asserted
         preference claim in Borrower's bankruptcy will become a part of the
         indebtedness and, at Lender's option, shall be payable by Borrower as
         provided above in the "EXPENDITURES BY LENDER" paragraph.

         SEVERABILITY.  If a court of competent jurisdiction finds any
         provision of this Agreement to be invalid or unenforceable as to any
         person or circumstance, such finding shall not render that provision
         invalid or unenforceable as to any other persons or circumstances.  If
         feasible, any such offending provision shall be deemed to be modified
         to be within the limits of enforceability or validity; however, if the
         offending provision cannot be so modified, it shall be stricken and
         all other provisions of this Agreement in all other respects shall
         remain valid and enforceable.

         SUCCESSOR INTERESTS.  Subject to the limitations set forth above on
         transfer of the Collateral, this Agreement shall be binding upon and
         inure to the benefit of the parties, their successors and assigns.

         WAIVER.  Lender shall not be deemed to have waived any rights under
         this Agreement unless such wavier is given in writing and signed by
         Lender.  No delay or omission on the part of Lender in exercising any
         right shall operate as a waiver of such right or any other right.  A
         wavier by Lender of a provision of this Agreement shall not prejudice
         or constitute a waiver of Lender's right otherwise to demand strict
         compliance with that provision or any other provision of this
         Argument.  No prior wavier by Lender, nor any course of dealing
         between Lender and Grantor, shall constitute a waiver of any of
         Lender's rights or of any of Grantor's obligations as to any future
         transactions.  Whenever the consent of Lender is required under this
         Agreement, the granting of such consent by Lender in any instance
         shall not constitute continuing consent to subsequent instances where
         such consent is required and in all cases such consent may be granted
         or withheld in the sole discretion of Lender.

         WAIVER OF CO-OBLIGOR'S RIGHTS.  If more than one person is obligated
         for the indebtedness, Borrower irrevocably waives, disclaims and
         relinquishes all claims against such other person which Borrower has
         or would otherwise have by virtue of payment of the indebtedness or
         any part thereof, specifically including but not limited to all rights
         of indemnity, contribution or exoneration.






<PAGE>   10
GRANTOR ACKNOWLEDGES HAVING READ ALL THE PROVISIONS OF THIS COMMERCIAL SECURITY
AGREEMENT, AND GRANTOR AGREES TO ITS TERMS.  THIS AGREEMENT IS DATED DECEMBER
5, 1996.

GRANTOR:

SEAMED CORPORATION



BY                                      BY /S/  EDGAR F. RAMPY
  -------------------------------         ------------------------------------- 
W. ROBERT BERG, PRESIDENT               EDGAR F. RAMPY, VICE PRESIDENT-FINANCE