957090103

                                    (CUSIP Number)                                    

Names of Reporting Persons.

I.R.S. Identification Nos. of above persons (entities only).

            David L. Payne

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ¨

(b)  ¨

SEC Use Only

Citizenship or Place of Organization

            United States

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With

  5.    Sole Voting Power

                1,672,341

  6.    Shared Voting Power

                173,916

  7.    Sole Dispositive Power

                1,672,341

  8.    Shared Dispositive Power

                173,916

Aggregate Amount Beneficially Owned by Each Reporting Person

            1,846,257

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)

¨

Percent of Class Represented by Amount in Row (9)

            5.47%

Type of Reporting Person (See Instructions)

            IN

Names of Reporting Persons.

I.R.S. Identification Nos. of above persons (entities only).

            Gibson Radio and Publishing Company

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)  ¨

(b)  ¨

SEC Use Only

Citizenship or Place of Organization

            California

Number of

Shares

Beneficially

Owned by

Each

Reporting

Person

With

  5.    Sole Voting Power

                528,837

  6.    Shared Voting Power

                0

  7.    Sole Dispositive Power

                528,837

  8.    Shared Dispositive Power

                0

Aggregate Amount Beneficially Owned by Each Reporting Person

            528,837

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)

¨

Percent of Class Represented by Amount in Row (9)

            1.65%

Type of Reporting Person (See Instructions)

            CO

(a)

Name of Issuer

Westamerica Bancorporation (“Westamerica”)

(b)

Address of Issuer’s Principal Executive Offices

1108 Fifth Avenue

San Rafael, California 94901

(a)

Name of Person Filing

This Amendment to Schedule 13G is being filed on behalf of the following persons (“Reporting Persons”)

(i) David L. Payne

(ii) Gibson Radio and Publishing Company (the “Company”)

(b)

Address of Principal Business Office or, if none, Residence

The principal business office of Mr. Payne is 4550 Mangels Blvd., Fairfield, CA 94585. The principal business office of the Company is 544 Curtola Parkway, Vallejo, CA 94590

(c)

Citizenship

David L. Payne: United States

Company: a California corporation

(d)

Title of Class of Securities

This Amendment to Schedule 13G is being filed with respect to the common stock, no par value, of Westamerica (“Common Stock”). The Reporting Persons’ percentage of ownership of Common Stock is based on 32,099,571 shares of Common Stock Outstanding and the ownership of options to purchase 1,660,461 shares of Common Stock (the “Options”) held by Mr. Payne.

As of December 31, 2005, (i) Mr. Payne beneficially owned 1,846,257 shares of Common Stock, of which 1,660,461 shares are attributable to the Options; and (ii) the Company beneficially owned 528,837 shares of Common Stock, none of which are attributable to the Options.

(e)

CUSIP Number

957090103

The information in items 1 and 5 through 11 on pages 2-3 of this Amendment to Schedule 13G is hereby incorporated by reference.

The 1,846,257 shares of Common Stock reported in row 9 on page 2 of this Amendment to Schedule 13G: (i) include 173,916 shares held in a revocable trust, as to which Mr. Payne is a co-trustee, and (ii) exclude the 528,837 shares owned by the Company, of which Mr. Payne is President and CEO. Mr. Payne expressly disclaims beneficial ownership of such shares.

Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following [ ].

Ownership of More than Five Percent on Behalf of Another Person.

The Company does not have any voting or dispositive power over the shares of Common Stock beneficially owned by Mr. Payne, and it expressly disclaims beneficial ownership of his shares.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person.

Not applicable.

Identification and Classification of Members of the Group

Not applicable.

Notice of Dissolution of Group

Not applicable.

Certification

(a)    

(b)    The following certification shall be included if the statement is filed pursuant to §240.13d-1(c):

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.