capitalization of 0.45 as compared to a maximum ratio of consolidated debt to total capitalization of 0.55 with the prior agreement. All other terms, including the financial and negative covenants, are customary for facilities of its type and consistent with the prior agreement in all material respects. 

The revolving credit facility provides, among other things, for the issuance of letters of credit that the company may utilize to guarantee performance under some of our operating contracts, as well as insurance, tax and other obligations in various jurisdictions. The facility also provides for customary fees and expense reimbursements and includes other covenants (including limitations on the incurrence of debt, mergers and other fundamental changes, limits on the company’s ability to encumber its assets for the benefit of others and asset sales) and events of default (including a change of control) that are customary for similar facilities. 

There were no borrowings outstanding under the amended and restated revolving credit agreement at March 31, 2010, and the full $450.0 million was available at March 31, 2010. There were no outstanding borrowings under the company’s previous revolving credit agreement at March 31, 2009. 

## Debt Costs 

The company capitalizes a portion of its interest costs incurred on borrowed funds used to construct vessels. Interest and debt costs incurred, net of interest capitalized for fiscal 2010, 2009, and 2008 and was approximately $1.7 million, $0.7 million, and $7.0 million, respectively. Interest costs capitalized during fiscal 2010, 2009 and 2008 was approximately $15.6 million, $13.8 million, and $10.5 million, respectively. 

## (5) EMPLOYEE RETIREMENT PLANS 

## U.S. Defined Benefit Pension Plan 

A defined benefit pension plan (pension plan) covers certain U.S. citizen employees and employees who are permanent residents of the United States. Benefits are based on years of service and employee compensation. Approximately 99% of the pension plan assets are invested in fixed income securities with the balance invested in cash and cash equivalents. The plan does not invest in Tidewater stock. The company’s policy is to contribute no less than the minimum required contribution by law and no more than the maximum deductible amount. The company contributed $4.7 million and $4.4 million to the defined benefit pension trust during fiscal 2010 and 2009, respectively. The company does not expect to contribute to the plan during fiscal 2011. 

In December 2009, the Board of Directors adopted amendments to the pension plan whereby effective December 31, 2010, the accrual of benefits would be discontinued. On that date, previously accrued pension benefits under the pension plan will be frozen for the approximately 70 active employees who participate in the plan. This change will not affect benefits earned by participants prior to January 1, 2011. Because future benefit accruals under the pension plan will be eliminated, the active employees who are participants in the pension plan will become participants in the company’s defined contribution retirement plan effective January 1, 2011. These changes will provide the company more predictable retirement plan costs and cash flows. By freezing the benefits, the company’s future benefit obligations and requirements for cash contributions for the frozen pension plan will be reduced. Any gains or losses associated with the curtailment of the pension plan were immaterial. 

## Supplemental Executive Retirement Plan 

The company also offers a supplemental retirement plan (supplemental plan) that provides pension benefits to certain employees in excess of those allowed under the company’s tax-qualified pension plan. Assets of this non-contributory defined benefit plan are held in a Rabbi Trust, invested in a variety of marketable securities, none of which is Tidewater stock. The Trust assets, which are included in “other assets” in the company’s consolidated balance sheet, are recorded at fair value with unrealized gains or losses included in other comprehensive income. Included in other assets at March 31, 2010 and 2009, is $16.2 million and $12.4 million, respectively, of investments held in a Rabbi Trust for the benefit of participants in the 

