Sanctuary Enhancement Act of 2008

Sanctuary Enhancement Act of 2008 - Amends the National Marine Sanctuaries Act to require that the National Marine Sanctuary System consist of national marine sanctuaries authorized or established by an Act of Congress (in addition to sanctuaries currently designated by the Secretary of Commerce) and marine national monuments. Sets forth the System's mission.

Requires the Secretary to prepare, maintain, and update an ecological classification of the nation's marine environment and an identification of maritime heritage resources as a national inventory of marine ecoregions and maritime heritage resources under U.S. jurisdiction.

Requires the Secretary to strive to include in the System, by 2030, sites that will incorporate a full range of the nation's marine ecoregions and rare and unique marine habitats, and a full range of maritime heritage resource areas.

Modifies various requirements regarding the designation and implementation of marine sanctuaries.

Expands the list of prohibited activities.

Amends provisions making a violation of a prohibited activity a criminal offense to: (1) exclude from those provisions foreign governments and their entities; and (2) add a requirement that a violation be knowing.

Increases the maximum term of imprisonment and the maximum civil fine.

Revises requirements regarding the preparation of fishing regulations applicable to a marine sanctuary.

Requires that System research and monitoring conducted, supported, or permitted by the Secretary be made available to the public unless the Secretary determines that public disclosure may result in the destruction of, loss of, or injury to any System resource.

Modifies requirements regarding special use permits.