Rigs to Reefs Act of 2003 - Amends the Outer Continental Shelf Lands Act to instruct the Secretary of the Interior to issue regulations authorizing the use for culture of marine organisms, an artificial reef, or scientific research of any offshore oil and gas platform decommissioned from service for oil and gas purposes.
Denies liability under Federal law of any former owner of an offshore oil and gas platform for costs or damages arising from use of it for culture of marine organisms, an artificial reef, or scientific research, unless such costs or damages arise from: (1) use of the platform by the person for development or production of oil or gas; or (2) another act or omission.
Amends the Internal Revenue Code of 1986 (relating to business-related credits) to establish an income tax credit for costs relating to converting offshore oil and gas platforms for culturing marine organisms.