<PAGE>   1
                                                                    EXHIBIT 10.1



                             BUSINESS LOAN AGREEMENT

<TABLE>
<CAPTION>
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   Principal     Loan Date     Maturity    Loan No.   Call    Collatera  l   Account     Officer   Initials
<S>              <C>          <C>          <C>                   <C>       <C>            <C>      <C>
$20,000,000.00   07-31-1997   07-05-2000   2000001               000       7996-314107    SAB10
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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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Borrower:       Seamed Corporation              Lender:     Keybank National Association
                14500 NE 87th Street                        Seattle Metropolitan Commercial
                Redmond, WA  98052                            Banking Center
                                                            700 Fifth Avenue
                                                            P.O. Box 90    WA-31-10-4871
                                                            Seattle, WA  98111-0090
===========================================================================================================
</TABLE>

THIS BUSINESS LOAN AGREEMENT between SEAMED CORPORATION ("Borrower") and KEYBANK
NATIONAL ASSOCIATION ("Lender") is made and executed on the following terms and
conditions. Borrower has received prior commercial loans from Lender or has
applied to Lender for a commercial loan or loans and other financial
accommodations, including those which may be described on any exhibit or
schedule attached to this Agreement. All such loans and financial
accommodations, together with all future loans and financial accommodations from
Lender to Borrower, are referred to in this Agreement individually as the "Loan"
and collectively as the "Loans." Borrower understands and agrees that: (a) in
granting, renewing, or extending any Loan, Lender is relying upon Borrower's
representations, warranties, and agreements, as set forth in this Agreement; (b)
the granting, renewing, or extending of any Loan by Lender at all times shall be
subject to lender's sole judgment and discretion; and (c) all such Loans shall
be and shall remain subject to the following terms and conditions of this
Agreement.

TERM. This Agreement shall be effective as of July 31, 1997, and shall continue
thereafter until all indebtedness of Borrower to Lender has been performed in
full and the parties terminate this Agreement in writing.

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 Business Loan Agreement, as this
    Business Loan Agreement may be amended or modified from time to time,
    together with all exhibits and schedules attached to this Business Loan
    Agreement from time to time.

    Borrower. The word "Borrower" means SEAMED CORPORATION. The word "Borrower"
    also includes, as applicable, all subsidiaries and affiliates of Borrower as
    provided below in the paragraph titled "Subsidiaries and Affiliates."

    CERCLA. The word "CERCLA" means the Comprehensive Environmental Response,
    Compensation, and Liability act of 1980, as amended.

<PAGE>   2

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 2
                                   (Continued)
Loan No. 2000001
================================================================================

    Cash Flow. The words "Cash Flow" mean net income after taxes, and exclusive
    of extraordinary gains and income, plus depreciation and amortization.

    Collateral. The word "Collateral" means and includes without limitation all
    property and assets granted as collateral security for a Loan, whether real
    or personal property, whether granted directly or indirectly, whether
    granted now or in the future, and whether granted in the form of a security
    interest, mortgage, deed of trust, assignment, pledge, chattel mortgage,
    chattel trust, factor's lien, equipment trust, conditional sale, trust
    receipt, lien, charge, lien or title retention contract, lease or
    consignment intended as a security device, or any other security or lien
    interest whatsoever, whether created by law, contract, or otherwise.

    Debt. The word "Debt" means all of Borrower's liabilities excluding
    Subordinated Debt.

    ERISA. The word "ERISA" means the Employee Retirement Income Security Act of
    1974, as amended.

    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."

    Grantor. The word "Grantor" means and includes without limitation each and
    all of the persons or entities granting a Security interest in any
    Collateral for the indebtedness, including without limitation all Borrowers
    granting such a security Interest.

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

    Indebtedness. The word "Indebtedness" means and includes without limitation
    all Loans, together with all other obligations, debts and liabilities of
    Borrower to Lender, or any one or more of them, as well as all claims by
    Lender against Borrower, or any one or more of them; whether now or
    hereafter existing, voluntary or involuntary, due or not due, absolute or
    contingent, liquidated or unliquidated; whether Borrower may be liable
    individually or jointly with others; whether Borrower may be obligated as a
    guarantor, surety, or otherwise; whether recovery upon such indebtedness may
    be or hereafter may become barred by any statute of limitations; and whether
    such indebtedness may be or hereafter may become otherwise unenforceable.

    Lender. The word "Lender" means KEYBANK NATIONAL ASSOCIATION, its successors
    and assigns.

    Liquid Assets. The words "Liquid Assets" mean Borrower's cash on hand plus
    Borrower's readily marketable securities.




                                      -2-
<PAGE>   3

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 3
                                   (Continued)
Loan No. 2000001
================================================================================

    Loan. The word "Loan" or Loans" means and includes without limitation any
    and all commercial loans and financial accommodations from Lender to
    Borrower, whether now or hereafter existing, and however evidenced,
    including without limitation those loans and financial accommodations
    described herein or described on any exhibit or schedule attached to this
    Agreement form time to time.

    Note. The word "Note" means and includes without limitation Borrower's
    promissory note or notes, if any, evidencing Borrower's Loan obligations in
    favor of Lender, as well as any substitute, replacement or refinancing note
    or notes therefor.

    Permitted Liens. The words "Permitted liens" mean: (a) liens and security
    interests securing indebtedness owed by Borrower to Lender; (b) liens for
    taxes, assessments, or similar charges either not yet due or being contested
    in good faith; (c) liens of materialmen, mechanics, warehousemen, or
    carriers or other like liens arising in the ordinary course of business and
    securing obligations which are not yet delinquent; (d) purchase money liens
    or purchase money security interests upon or in any property acquired or
    held by Borrower in the ordinary course of business to secure indebtedness
    outstanding on the date of this Agreement or permitted to be incurred under
    the paragraph of this Agreement titled "Indebtedness and Liens"; (e) liens
    and security interests which, as of the date of this Agreement, have been
    disclosed to and approved by the Lender in writing; and (f) those liens and
    security interests which in the aggregate constitute an immaterial and
    insignificant monetary amount with respect to the net value of Borrower's
    assets.

    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.

    Security Agreement. The words "Security Agreement" mean and include without
    limitation any agreements, promises, covenants, arrangements, understandings
    or other agreements, whether crated by law, contract, or otherwise,
    evidencing, governing, representing, or creating a Security Interest.

    Security Interest. The words "Security Interest" mean and include without
    limitation any type of collateral security, whether in the form of a lien,
    charge, mortgage, deed of trust, assignment, pledge, chattel mortgage,
    chattel trust, factor's lien, equipment trust, conditional sale, trust
    receipt, lien or title retention contract, lease or consignment intended as
    a security device, or any other security or lien interest whatsoever,
    whether created by law, contract, or otherwise.

    SARA. The word "SARA" means the Superfund Amendments and Reauthorization Act
    of 1986 as now or hereafter amended.



                                      -3-
<PAGE>   4

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 4
                                   (Continued)
Loan No. 2000001
================================================================================

    Subordinated Debt. The words "Subordinated Debt" mean indebtedness and
    liabilities of Borrower which have been subordinated by written agreement to
    indebtedness owed by Borrower to Lender in form and substance acceptable to
    Lender.

    Tangible Net Worth. The words "Tangible Net Worth" mean Borrower's total
    assets excluding all intangible assets (i.e., goodwill, trademarks, patents,
    copyrights, organizational expenses, and similar intangible items, but
    including leaseholds and leasehold improvements) less total Debt.

    Working Capital. The words "Working Capital" mean Borrower's current assets,
    excluding prepaid expenses, less Borrower's current liabilities.

CONDITIONS PRECEDENT TO EACH ADVANCE. Lender's obligation to make the initial
Loan Advance and each subsequent Loan Advance under this Agreement shall be
subject to the fulfillment to Lender's satisfaction of all of the conditions set
forth in this Agreement and in the Related Documents.

    Loan Documents. Borrower shall provide to Lender in form satisfactory to
    Lender the following documents for the Loan: (a) the Note, (b) Security
    Agreements granting to Lender security interests in the Collateral, (c)
    Financing Statements perfecting Lender's Security Interests; (d) evidence of
    insurance as required below; and (e) any other documents required under this
    Agreement or by Lender or its counsel.

    Borrower's Authorization. Borrower shall have provided in form and substance
    satisfactory to Lender properly certified resolutions, duly authorizing the
    execution and delivery of this Agreement, the Note and the Related
    Documents, and such other authorizations and other documents and instruments
    as Lender or its counsel, in their sole discretion, may require.

    Payment of Fees and Expenses. Borrower shall have paid to Lender all fees,
    charges, and other expenses which are then due and payable as specified in
    this Agreement or any Related Document.

    Representations and Warranties. The representations and warranties set forth
    in this Agreement, in the Related Documents, and in any document or
    certificate delivered to Lender under this Agreement are true and correct.

    No Event of Default. There shall not exist at the time of any advance a
    condition which would constitute an Event of Default under this Agreement.

REPRESENTATIONS AND WARRANTIES. Borrower represents and warrants to Lender, as
of the date of this Agreement, as of the date of each disbursement of Loan
proceeds, as of the date of any renewal, extension or modification of any Loan,
and at all times any indebtedness exists:



                                      -4-
<PAGE>   5

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 5
                                   (Continued)
Loan No. 2000001
================================================================================

    Organization. Borrower is a corporation which is duly organized, validly
    existing, and in good standing under the laws of the State of Washington and
    is validly existing and in good standing in all states in which Borrower is
    doing business. Borrower has the full power and authority to own its
    properties and to transact the businesses in which it is presently engaged
    or presently proposes to engage. Borrower also is duly qualified as a
    foreign corporation and is in good standing in all states in which the
    failure to so qualify would have a material adverse effect on its businesses
    or financial condition.

    Authorization. The execution, delivery, and performance of this Agreement
    and all Related Documents by Borrower, to the extent to be executed,
    delivered or performed by Borrower, have been duly authorized by all
    necessary action by Borrower; do not require the consent or approval of any
    other person, regulatory authority or governmental body; 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 Borrower or (b) any law,
    governmental regulation, court decree, or order applicable to Borrower.

    Financial Information. Each financial statement of Borrower supplied to
    Lender truly and completely disclosed Borrower's financial condition as of
    the date of the statement, and there has been no material adverse change in
    Borrower's financial condition subsequent to the date of the most recent
    financial statement supplied to Lender. Borrower has no material contingent
    obligations except as disclosed in such financial statements.

    Legal Effect. This Agreement constitutes, and any instrument or agreement
    required hereunder to be given by Borrower when delivered will constitute,
    legal, valid and binding obligations of Borrower enforceable against
    Borrower in accordance with their respective terms.

    Properties. Except as contemplated by this Agreement or as previously
    disclosed in Borrower's financial statements or in writing to Lender and as
    accepted by Lender, and except for property tax liens for taxes not
    presently due and payable, Borrower owns and has good title to all of
    Borrower's properties free and clear of all Security Interests, and has not
    executed any security documents or financing statements relating to such
    properties. All of Borrower's properties are titled in Borrower's legal
    name, and Borrower has not used, or filed a financing statement under, any
    other name for at least the last five (5) years.

    Hazardous Substances. The terms "hazardous waste," "hazardous substance,"
    "disposal," "release," and "threatened release," as used in this Agreement,
    shall have the same meanings as set forth in the "CERCLA," "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. Except as disclosed to and acknowledged by
    Lender in writing, Borrower represents and warrants that: (a) During the
    period of Borrower's



                                      -5-
<PAGE>   6

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 6
                                   (Continued)
Loan No. 2000001
================================================================================

    ownership of the properties, there has been no use, generation, manufacture,
    storage, treatment, disposal, release or threatened release of any hazardous
    waste or substance by any person on, under, about or from any of the
    properties. (b) Borrower has no knowledge of, or reason to believe that
    there has been (i) any use, generation, manufacture, storage, treatment,
    disposal, release, or threatened release of any hazardous waste or substance
    on, under, about or from the properties by any prior owners or occupants of
    any of the properties, or (ii) any actual or threatened litigation or claims
    of any kind by any person relating to such matters. (c) Neither Borrower nor
    any tenant, contractor, agent or other authorized user of any of the
    properties shall use, generate, manufacture, store, treat, dispose of, or
    release any hazardous waste or substance on, under, about or from any of the
    properties; and any such activity shall be conducted in compliance with all
    applicable federal, state, and local laws, regulations, and ordinances,
    including without limitation those laws, regulations and ordinances
    described above. Borrower authorizes Lender and its agents to enter upon the
    properties to make such inspections and tests as Lender may deem appropriate
    to determine compliance of the properties with this section of the
    Agreement. Any inspections or tests made by Lender shall be at Borrower's
    expense and for Lender's purposes only and shall not be construed to create
    any responsibility or liability on the part of Lender to Borrower or to any
    other person. The representations and warranties contained herein are based
    on Borrower's due diligence in investigating the properties for hazardous
    waste and hazardous substances. Borrower hereby (a) releases and waives any
    future claims against Lender for indemnity or contribution in the event
    Borrower 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,
    losses, liabilities, damages, penalties, and expenses which Lender may
    directly or indirectly sustain or suffer resulting from a breach of this
    section of the Agreement or as a consequence of any use, generation,
    manufacture, storage, disposal, release or threatened release occurring
    prior to Borrower's ownership or interest in the properties, whether or not
    the same was or should have been known to Borrower. The provisions of this
    section of the Agreement, including the obligation to indemnify, shall
    survive the payment of the indebtedness and the termination or expiration of
    this Agreement and shall not be affected by Lender's acquisition of any
    interest in any of the properties, whether by foreclosure or otherwise.

    Litigation and Claims. No litigation, claim, investigation, administrative
    proceeding or similar action (including those for unpaid taxes) against
    Borrower is pending or threatened, and no other event has occurred which may
    materially adversely affect Borrower's financial condition or properties,
    other than litigation, claims or other events, if any, that have been
    disclosed to and acknowledged by Lender in writing.

    Taxes. To the best of Borrower's knowledge, all tax returns and reports of
    Borrower that are or were required to be filed, have been filed, and all
    taxes, assessments and other governmental charges have been paid in full,
    except those presently being or to be contested by Borrower in good faith in
    the ordinary course of business and for which adequate reserves have been
    provided.



                                      -6-
<PAGE>   7

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 7
                                   (Continued)
Loan No. 2000001
================================================================================

    Binding Effect. This Agreement, the Note, and all of the Related Documents
    are binding upon Borrower as well as upon Borrower's successors,
    representatives and assigns, and are legally enforceable in accordance with
    their respective terms.

    Commercial Purposes. Borrower intends to use the Loan proceeds solely for
    business or commercial related purposes.

    Employee Benefit Plans. Each employee benefit plan as to which Borrower may
    have any liability complies in all material respects with all applicable
    requirements of law and regulations, and (i) no Reportable Event nor
    Prohibited Transaction (as defined in ERISA) has occurred with respect to
    any such plan, (ii) Borrower has not withdrawn from any such plan or
    initiated steps to do so, (iii) no steps have been taken to terminate any
    such plan, and (iv) there are no unfunded liabilities other than those
    previously disclosed to Lender in writing.

    Location of Borrower's Offices and Records. Borrower's place of business, or
    Borrower's Chief executive office, if Borrower has more than one place of
    business, is located at 14500 NORTHEAST 87TH STREET, REDMOND, WA 98052.
    Unless Borrower has designated otherwise in writing this location is also
    the office or offices where Borrower keeps its records concerning the
    Collateral.

    Information. All information heretofore or contemporaneously herewith
    furnished by Borrower to Lender for the purposes of or in connection with
    this Agreement or any transaction contemplated hereby is, and all
    information hereafter furnished by or on behalf of Borrower to Lender will
    be, true and accurate in every material respect on the date as of which such
    information is dated or certified; and none of such information is or will
    be incomplete by omitting to state any material fact necessary to make such
    information not misleading.

    Survival of Representations and Warranties. Borrower understands and agrees
    that Lender, without independent investigation, is relying upon the above
    representations and warranties in extending Loan Advances to Borrower.
    Borrower further agrees that the foregoing representations and warranties
    shall be continuing in nature and shall remain in full force and effect
    until such time as Borrower's indebtedness shall be paid in full, or until
    this Agreement shall be terminated in the manner provided above, whichever
    is the last to occur.

AFFIRMATIVE COVENANTS. Borrower covenants and agrees with Lender that, while
this Agreement is in effect, Borrower will:

    Litigation. Promptly inform Lender in writing of (a) all material adverse
    changes in Borrower's financial condition, and (b) all existing and all
    threatened litigation, claims, investigations, administrative proceedings or
    similar actions affecting Borrower or any Guarantor which could materially
    affect the financial condition of Borrower or the financial condition of any
    Guarantor.



                                      -7-
<PAGE>   8

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 8
                                   (Continued)
Loan No. 2000001
================================================================================

    Financial Records. Maintain its books and records in accordance with
    generally accepted accounting principles, applied on a consistent basis, and
    permit Lender to examine and audit Borrower's books and records at all
    reasonable times.

    Financial Statements. Furnish Lender with, as soon as available, but in no
    event later than ninety (90) days after the end of each fiscal year,
    Borrower's balance sheet and income statement for the year ended, audited by
    a certified public accountant satisfactory to Lender, and, as soon as
    available, but in no event later than ninety (90) days after the end of each
    fiscal quarter, Borrower's balance sheet and profit and loss statement for
    the period ended, prepared and certified as correct to the best knowledge
    and belief by Borrower's chief financial officer or other officer or person
    acceptable to Lender. All financial reports required to be provided under
    this Agreement shall be prepared in accordance with generally accepted
    accounting principles, applied on a consistent basis, and certified by
    Borrower as being true and correct.

    Additional Information. Furnish such additional information and statements,
    lists of assets and liabilities, agings of receivables and payables,
    inventory schedules, budgets, forecasts, tax returns, and other reports with
    respect to Borrower's financial condition and business operations as Lender
    may request from time to time.

    Financial Covenants and Ratios. Comply with the following covenants and
    ratios:

        Net Worth Ratio. Maintain a ratio of Total Liabilities to Tangible Net
        Worth of less than 1.25 to 1.00. Except as provided above, all
        computations made to determine compliance with the requirements
        contained in this paragraph shall be made in accordance with generally
        accepted accounting principles, applied on a consistent basis, and
        certified by Borrower as being true and correct.

        Insurance. Maintain fire and other risk insurance, public liability
        insurance, and such other insurance as Lender may require with respect
        to Borrower's properties and operations, in form, amounts, coverages and
        with insurance companies reasonably acceptable to Lender. Borrower, 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 ten (10) days' prior written notice to Lender. 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 Borrower or any other person. In connection with all policies
        covering assets in which Lender holds or is offered a security interest
        for the Loans, Borrower will provide Lender with such loss payable or
        other endorsements as Lender may require.

    Insurance Reports. Furnish to Lender, upon request of Lender, reports on
    each existing insurance policy showing such information as Lender may
    reasonably request, including without limitation the following: (a) the name
    of the insurer; (b) the risks insured; (c) the amount of the policy; (d) the
    properties insured; (e) the then current property values on the



                                      -8-
<PAGE>   9

07-31-1997                  BUSINESS LOAN AGREEMENT                       Page 9
                                   (Continued)
Loan No. 2000001
================================================================================

    basis of which insurance has been obtained, and the manner of determining
    those values; and (f) the expiration date of the policy. In addition, upon
    request of Lender (however not more often then annually), Borrower will have
    an independent appraiser satisfactory to Lender determine, as applicable,
    the actual cash value or replacement cost of any Collateral. The cost of
    such appraisal shall be paid by Borrower.

    Other Agreements. Comply with all terms and conditions of all other
    agreements, whether now or hereafter existing, between Borrower and any
    other party and notify Lender immediately in writing of any default in
    connection with any other such agreements.

    Loan Proceeds. Use all Loan proceeds solely for Borrower's business
    operations, unless specifically consented to the contrary by Lender in
    writing.

    Taxes, Charges and Liens. Pay and discharge when due all of the indebtedness
    and obligations, including without limitation all assessments, taxes,
    governmental charges, levies and liens, of every kind and nature, imposed
    upon Borrower or its properties, income, or profits, prior to the date on
    which penalties would attach, and all lawful claims that, if unpaid, might
    become a lien or charge upon any of Borrower's properties, income, or
    profits, Provided however, Borrower will not be required to pay and
    discharge any such assessment, tax, charge, levy, lien or claim so long as
    (a) the legality of the same shall be contested in good faith by appropriate
    proceedings, and (b) Borrower shall have established on its books adequate
    reserves with respect to such contested assessment, tax, charge, levy, lien,
    or claim in accordance with generally accepted accounting practices.
    Borrower, upon demand of Lender, will furnish to Lender evidence of payment
    of the assessments, taxes, charges, levies, liens and claims and will
    authorize the appropriate governmental official to deliver to Lender at any
    time a written statement of any assessments, taxes, charges, levies, liens
    and claims against Borrower's properties, income, or profits.

    Performance. Perform and comply with all terms, conditions, and provisions
    set forth in this Agreement and in the Related Documents in a timely manner,
    and promptly notify Lender if Borrower learns of the occurrence of any event
    which constitutes an Event of Default under this Agreement or under any of
    the Related Documents.

    Operations. Maintain executive and management personnel with substantially
    the same qualifications and experience as the present executive and
    management personnel; provide written notice to Lender of any change in
    executive and management personnel; conduct its business affairs in a
    reasonable and prudent manner and in compliance with all applicable federal,
    state and municipal laws, ordinances, rules and regulations respecting its
    properties, charters, businesses and operations, including without
    limitation, compliance with the Americans With Disabilities Act and with all
    minimum funding standards and other requirements of ERISA and other laws
    applicable to Borrower's employee benefit plans.

    Inspection. Permit employees or agents of Lender at any reasonable time to
    inspect any and all Collateral for the Loan or Loans and Borrower's other
    properties and to examine or audit



                                      -9-
<PAGE>   10

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 10
                                   (Continued)
Loan No. 2000001
================================================================================

    Borrower's books, accounts, and records and to make copies and memoranda of
    Borrower's books, accounts and records. If Borrower now or at any time
    hereafter maintains any records (including without limitation computer
    generated records and computer software programs for the generation of such
    records) in the possession of a third party, Borrower, upon request of
    Lender, shall notify such party to permit Lender free access to such records
    at all reasonable times and to provide Lender with copies of any records it
    may request; all at Borrower's expense.

    Compliance Certificate. Unless waived in writing by Lender, provide Lender
    at least annually and at the time of each disbursement of Loan proceeds with
    a certificate executed by Borrower's chief financial officer, or other
    officer or person acceptable to Lender, certifying that the representations
    and warranties set forth in this Agreement are true and correct as of the
    date of the certificate and further certifying that, as of the date of the
    certificate, no Event of Default exists under this Agreement.

    Environmental Compliance and Reports. Borrower shall comply in all respects
    with all environmental protection federal, state and local laws, statutes,
    regulations and ordinances; not cause or permit to exist, as a result of an
    intentional or unintentional action or omission on its part or on the part
    of any third party, on property owned and/or occupied by Borrower, any
    environmental activity where damage may result to the environment, unless
    such environmental activity is pursuant to and in compliance with the
    conditions of a permit issued by the appropriate federal, state or local
    governmental authorities; shall furnish to Lender promptly and in any event
    within thirty (30) days after receipt thereof a copy of any notice, summons,
    lien, citation, directive, letter or other communication from any
    governmental agency or instrumentality concerning any intentional or
    unintentional action or omission on Borrower's part in connection with any
    environmental activity whether or not there is damage to the environment
    and/or other natural resources.

    Additional Assurances. Make, execute and deliver to Lender such promissory
    notes, mortgages, deeds of trust, security agreements, financing statements,
    instruments, documents and other agreements as Lender or its attorneys may
    reasonably request to evidence and secure the Loans and to perfect all
    Security Interests.

NEGATIVE COVENANTS. Borrower covenants and agrees with Lender that while this
Agreement is in effect, Borrower shall not, without the prior written consent of
Lender:

    Indebtedness and Liens. (a) Except for trade debt incurred in the normal
    course of business and indebtedness to Lender contemplated by this
    Agreement, create, incur or assume indebtedness for borrowed money,
    including capital leases, (b) except as allowed as a Permitted Lien, sell,
    transfer, mortgage, assign, pledge, lease, grant a security interest in, or
    encumber any of Borrower's assets, or (c) sell with recourse any of
    Borrower's accounts, except to Lender.



                                      -10-
<PAGE>   11

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 11
                                   (Continued)
Loan No. 2000001
================================================================================

    Continuity of Operations. (a) Engage in any business activities
    substantially different than those in which Borrower is presently engaged,
    (b) cease operations, liquidate, merge, transfer, acquire or consolidate
    with any other entity, change ownership, change its name, dissolve or
    transfer or sell Collateral out of the ordinary course of business, (c) pay
    any dividends on Borrower's stock (other than dividends payable in its
    stock), provided, however that notwithstanding the foregoing, but only so
    long as no Event of Default has occurred and is continuing or would result
    from the payment of dividends, if Borrower is a "Subchapter S Corporation"
    (as defined in the Internal Revenue Code of 1988, as amended), Borrower may
    pay cash dividends on its stock to its shareholders from time to time in
    amounts necessary to enable the shareholders to pay income taxes and make
    estimated income tax payments to satisfy their liabilities under federal and
    state law which arise solely from their status as Shareholders of a
    Subchapter S Corporation because of their ownership of shares of stock of
    Borrower, or (d) purchase or retire any of Borrower's outstanding shares or
    alter or amend Borrower's capital structure.

    Loans, Acquisitions and Guaranties. (a) Loan, invest in or advance money or
    assets, (b) purchase, create or acquire any interest in any other enterprise
    or entity, or (c) incur any obligation as surety or guarantor other than in
    the ordinary course of business.

CESSATION OF ADVANCES. If Lender has made any commitment to make any Loan to
Borrower, whether under this Agreement or under any other agreement, Lender
shall have no obligation to make Loan Advances or to disburse Loan proceeds if:
(a) Borrower or any Guarantor is in default under the terms of this Agreement or
any of the related Documents or any other agreement that Borrower or any
Guarantor has with Lender; (b) Borrower or any Guarantor becomes insolvent,
files a petition in bankruptcy or similar proceedings, or is adjudged a
bankrupt; (c) there occurs a material adverse change in Borrower's financial
condition, in the financial condition of any Guarantor, or in the value of any
Collateral securing any Loan; or (d) any Guarantor seeks, claims or otherwise
attempts to limit, modify or revoke such Guarantor's guaranty of the Loan or any
other loan with Lender.

ADDITIONAL AFFIRMATIVE COVENANTS. Borrower covenants and agrees with Lender
that, while this Agreement is in effect, Borrower will maintain a minimum
interest coverage ratio of 2.0 to 1.0 measured quarterly. Interest coverage
shall be defined as earnings before interest and taxes divided by interest.
Borrower covenants and agrees with Lender that, while this Agreement is in
effect, all dividends shall be materially restricted without prior bank consent.
Borrower covenants and agrees with Lender that, while this Agreement is in
effect, advances will be limited to 85% of eligible account receivables and 50%
of eligible inventory. Borrower shall certify in writing to the bank on a
quarterly basis that they have been within the parameters of the borrowing
formula at all times during the quarter and that they are in compliance with all
covenants. Borrower covenants and agrees with Lender that, while this Agreement
is in effect, Borrower will maintain a ratio of Total Liabilities to Tangible
Net Worth of less than 1.25 to 1.00 measured quarterly.



                                      -11-
<PAGE>   12

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 12
                                   (Continued)
Loan No. 2000001
================================================================================

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

    Default on Indebtedness. Failure of Borrower to make any payment when due on
    the Loans.

    Other Defaults. Failure of Borrower or any Grantor to comply with or to
    perform when due any other term, obligation, covenant or condition contained
    in this Agreement or in any of the Related Documents, or failure of Borrower
    to comply with or to perform any other term, obligation, covenant or
    condition contained in any other agreement between Lender and Borrower.

    Default in Favor of Third Parties. Should Borrower or any Grantor default
    under any loan, extension of credit, security agreement, purchase or sales
    agreement, or any other agreement, in favor of any other creditor or person
    that may materially affect any of Borrower's property or Borrower's or any
    Grantor's ability to repay the Loans or perform their respective obligations
    under this Agreement or any of the Related Documents.

    False Statements. Any warranty, representation or statement made or
    furnished to Lender by or on behalf of Borrower or any Grantor under this
    Agreement or the Related Documents is false or misleading in any material
    respect at the time made or furnished, or becomes false or misleading at any
    time thereafter.

    Defective Collateralization. This Agreement or any of the Related Documents
    ceases to be in full force and effect (including failure of any Security
    Agreement to create a valid and perfected Security Interest) at any time and
    for any reason.

    Insolvency. The dissolution or termination of Borrower's existence as a
    going business, the insolvency of Borrower, the appointment of a receiver
    for any part of Borrower'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 Borrower.

    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 Borrower, any creditor
    of any Grantor against any collateral securing the indebtedness, or by any
    governmental agency. This includes a garnishment, attachment, or levy on or
    of any of Borrower's deposit accounts with Lender. However, this Event of
    Default shall not apply if there is a good faith dispute by Borrower or
    Grantor, as the case may be, as to the validity or reasonableness of the
    claim which is the basis of the creditor or forfeiture proceedings, and if
    Borrower or Grantor gives Lender written notice of the creditor or
    forfeiture proceeding and furnishes reserves or a surety bond for the
    creditor or forfeiture proceeding satisfactory to Lender.



                                      -12-
<PAGE>   13

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 13
                                   (Continued)
Loan No. 2000001
================================================================================

    Events Affecting Guarantor. Any of the preceding events occurs with respect
    to any Guarantor of any of the indebtedness or any Guarantor dies or becomes
    incompetent, or revokes or disputes the validity of, or liability under, any
    Guaranty of the indebtedness. Lender, at its option, may, but shall not be
    required to, permit the Guarantor's estate to assume unconditionally the
    obligations arising under the guaranty in a manner satisfactory to Lender,
    and, in doing so, cure the Event of Default.

    Change in Ownership. Any change in ownership of twenty-five percent (25%) or
    more of the common stock of Borrower.

    Adverse Change. A material adverse change occurs in Borrower's financial
    condition, or Lender believes the prospect of payment or performance of the
    indebtedness is impaired.

    Right to Cure. If any default, other than a Default on Indebtedness, is
    curable and if Borrower or Grantor, as the case may be, has not been given a
    notice of a similar default within the preceding twelve (12) months, it may
    be cured (and no Event of Default will have occurred) if Borrower or
    Grantor, as the case may be, after receiving written notice from Lender
    demanding cure of such default: (a) cures the default within fifteen (15)
    days; or (b) if the cure requires more than fifteen (15) days, immediately
    initiates steps which Lender deems in Lender's sole discretion to be
    sufficient to cure the default and thereafter continues and completes all
    reasonable and necessary steps sufficient to produce compliance as soon as
    reasonably practical.

EFFECT OF AN EVENT OF DEFAULT. If any Event of Default shall occur, except where
otherwise provided in this Agreement or the Related Documents, all commitments
and obligations of Lender under this Agreement or the Related Documents or any
other agreement immediately will terminate (including any obligation to make
Loan Advances or disbursements), and, at Lender's option, all indebtedness
immediately will become due and payable, all without notice of any kind to
Borrower, except that in the case of an Event of Default of the type described
in the "Insolvency" subsection above, such acceleration shall be automatic and
not optional. In addition, Lender shall have all the rights and remedies
provided in the Related Documents or available at law, in equity, or otherwise.
Except as may be prohibited by applicable law, all of Lender's rights and
remedies 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 Borrower or of any Grantor shall not affect Lender's right to
declare a default and to exercise its rights and remedies.

MISCELLANEOUS PROVISIONS. The following miscellaneous provisions are a 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.



                                      -13-
<PAGE>   14

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 14
                                   (Continued)
Loan No. 2000001
================================================================================

    Applicable Law. This Agreement has been delivered to lender and accepted by
    Lender in the State of Washington. If there is a lawsuit, Borrower agrees
    upon Lender's request to submit to the jurisdiction of the courts of King or
    Pierce County, the State of Washington, Lender and Borrower hereby waive the
    right to any jury trial in any action, proceeding, or counterclaim brought
    by either Lender or Borrower against the other. This Agreement shall be
    governed by and construed in accordance with the laws of the State of
    Washington.

    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 Borrower under
    this Agreement shall be joint and several, and all references to Borrower
    shall mean each and every Borrower. This means that each of the persons
    signing below is responsible for all obligations in this Agreement.

    Consent to Loan Participation. Borrower agrees and consents to Lender's sale
    or transfer, whether now or later, of one or more participation interests in
    the Loans to one or more purchasers, whether related or unrelated to Lender.
    Lender may provide, without any limitation whatsoever, to any one or more
    purchasers, or potential purchasers, any information or knowledge Lender may
    have about Borrower or about any other matter relating to the Loan, and
    Borrower hereby waives any rights to privacy it may have with respect to
    such matters. Borrower additionally waives any and all notices of sale of
    participation interests, as well as all notices of any repurchase of such
    participation interests. Borrower also agrees that the purchasers of any
    such participation interests will be considered as the absolute owners of
    such interests in the Loans and will have all the rights granted under the
    participation agreement or agreements governing the sale of such
    participation interests. Borrower further waives all rights of offset or
    counterclaim that it may have now or later against Lender or against any
    purchaser of such a participation interest and unconditionally agrees that
    either Lender or such purchaser may enforce Borrower's obligation under the
    Loans irrespective of the failure or insolvency of any holder of any
    interest in the Loans. Borrower further agrees that the purchaser of any
    such participation interests may enforce its interests irrespective of any
    personal claims or defenses that Borrower may have against Lender.

    Costs and Expenses. Borrower agrees to pay upon demand all of Lender's
    expenses, including without limitation attorneys' fees, incurred in
    connection with the preparation, execution, enforcement, modification and
    collection of this Agreement or in connection with the Loans made pursuant
    to this Agreement. Lender may pay someone else to help collect the Loans and
    to enforce this Agreement, and Borrower will pay that amount. This includes,
    subject to any limits under applicable law, Lender's attorneys' fees and
    Lender's legal expenses, whether or not there is a lawsuit, including
    attorneys' fees for bankruptcy proceedings (including efforts to modify or
    vacate any automatic stay or injunction), appeals, and any anticipated
    post-judgment collection services. Borrower also will pay any court costs,
    in addition to all other sums provided by law.



                                      -14-
<PAGE>   15

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 15
                                   (Continued)
Loan No. 2000001
================================================================================

    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 the 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 Borrower,
    notice to any Borrower will constitute notice to all Borrowers. For notice
    purposes, Borrower will keep Lender informed at all times of Borrower's
    current address(es).

    Severability. If a court of competent jurisdiction finds any provision of
    this Agreement to be invalid or unenforceable as to any person or
    circumstances, 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.

    Subsidiaries and Affiliates of Borrower. To the extent the context of any
    provisions of this Agreement makes it appropriate, including without
    limitation any representation, warranty or covenant, the word "Borrower" as
    used herein shall include all subsidiaries and affiliates of Borrower.
    Notwithstanding the foregoing however, under no circumstances shall this
    Agreement be construed to require Lender to make any Loan or other financial
    accommodation to any subsidiary or affiliate of Borrower.

    Successors and Assigns. All covenants and agreements contained by or on
    behalf of Borrower shall bind its successors and assigns and shall inure to
    the benefit of Lender, its successors and assigns. Borrower shall not,
    however, have the right to assign its rights under this Agreement or any
    interest therein, without the prior written consent of Lender.

    Survival. All warranties, representations, and covenants made by Borrower in
    this Agreement or in any certificate or other instrument delivered by
    Borrower to Lender under this Agreement shall be considered to have been
    relied upon by Lender and will survive the making of the Loan and delivery
    to Lender of the Related Documents, regardless of any investigation made by
    Lender or on Lender's behalf.

    Waiver. Lender shall not be deemed to have waived any rights under this
    Agreement unless such waiver 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 waiver 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 Agreement. No prior waiver by Lender, nor any
    course of dealing between Lender and Borrower, or between Lender and any
    Grantor, shall constitute a waiver of any of



                                      -15-
<PAGE>   16

07-31-1997                  BUSINESS LOAN AGREEMENT                      Page 16
                                   (Continued)
Loan No. 2000001
================================================================================

    Lender's rights or of any obligations of Borrower or of any Grantor 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 in subsequent instances where such consent
    is required, and in all cases such consent may be granted or withheld in the
    sole discretion of Lender.

BORROWER ACKNOWLEDGES HAVING READ ALL THE PROVISIONS OF THIS BUSINESS LOAN
AGREEMENT, AND BORROWER AGREES TO ITS TERMS. THIS AGREEMENT IS DATED AS OF
JULY 31, 1997.

BORROWER:

SEAMED CORPORATION



By    /s/ EDGAR F. RAMPY
  ---------------------------------------------
      EDGAR F. RAMPY, Vice President, Treasurer
      and Chief Financial Officer


LENDER:

KEYBANK NATIONAL ASSOCIATION


By   /s/ SARAH A. BULLOCK
  ---------------------------------------------
    Authorized Officer










                                      -16-