**Exhibit 31   Certifications**I, Don J. McGrath certify that:     1. I have reviewed this report on Form 10-Q of BancWest Corporation;     2. Based on my knowledge, this report does not contain any untrue statement of a materialfact or omit to state a material fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading with respect to the periodcovered by this report;     3. Based on my knowledge, the financial statements, and other financial informationincluded in this report, fairly present in all material respects the financial condition, resultsof operations and cash flows of the registrant as of, and for, the periods presented in thisreport;     4. The registrant’s other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the registrant and have:     a) Designed such disclosure controls and procedures, or caused such disclosure controlsand procedures to be designed under our supervision, to ensure that material information relatingto the registrant, including its consolidated subsidiaries, is made known to us by others withinthose entities, particularly during the period in which this report is being prepared;     b) Evaluated the effectiveness of the registrant’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of the disclosure controls andprocedures, as of the end of the period covered by this report based on such evaluation; and     c) Disclosed in this report any change in the registrant’s internal control overfinancial reporting that occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that has materially affected,or is reasonably likely to materially affect, the registrant’s internal control over financialreporting; and     5. The registrant’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to the registrant’s auditors andthe audit committee of the registrant’s board of directors (or persons performing the equivalentfunctions):     a) All significant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely to adversely affect theregistrant’s ability to record, process, summarize and report financial information; and     b) Any fraud, whether or not material, that involves management or other employees whohave a significant role in the registrant’s internal control over financial reporting.      /s/ Don J. McGrath     Don J. McGrath  President and Chief Executive Officer     Date: November 14, 2005  
 

 
**Exhibit 31   Certifications**I, Douglas C. Grigsby, certify that:     1. I have reviewed this report on Form 10-Q of BancWest Corporation;     2. Based on my knowledge, this report does not contain any untrue statement of a materialfact or omit to state a material fact necessary to make the statements made, in light of thecircumstances under which such statements were made, not misleading with respect to the periodcovered by this report;     3. Based on my knowledge, the financial statements, and other financial informationincluded in this report, fairly present in all material respects the financial condition, resultsof operations and cash flows of the registrant as of, and for, the periods presented in thisreport;     4. The registrant’s other certifying officer and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) for the registrant and have:     a) Designed such disclosure controls and procedures, or caused such disclosure controlsand procedures to be designed under our supervision, to ensure that material information relatingto the registrant, including its consolidated subsidiaries, is made known to us by others withinthose entities, particularly during the period in which this report is being prepared;     b) Evaluated the effectiveness of the registrant’s disclosure controls and proceduresand presented in this report our conclusions about the effectiveness of the disclosure controlsand procedures, as of the end of the period covered by this report based on such evaluation; and     c) Disclosed in this report any change in the registrant’s internal control overfinancial reporting that occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that has materially affected,or is reasonably likely to materially affect, the registrant’s internal control over financialreporting; and     5. The registrant’s other certifying officer and I have disclosed, based on our mostrecent evaluation of internal control over financial reporting, to the registrant’s auditors andthe audit committee of the registrant’s board of directors (or persons performing the equivalentfunctions):     a) All significant deficiencies and material weaknesses in the design or operation ofinternal control over financial reporting which are reasonably likely to adversely affect theregistrant’s ability to record, process, summarize and report financial information; and     b) Any fraud, whether or not material, that involves management or other employees whohave a significant role in the registrant’s internal control over financial reporting.      /s/ Douglas C. Grigsby     Douglas C. Grigsby  Executive Vice President, Chief Financial Officer and Treasurer     Date: November 14, 2005