Diligence , at the Naval Air Station Annex in Southampton.

The 210-foot United States Coast Guard cutter will be open to the public from 1 p.m. to 4 p.m.

The vessel, fitted with a helicopter landing deck, is responsible for enforcing American laws in coastal waters and on the high seas.

Peacetime missions include recreational boating safety; search and rescue; environmental protection; and enforcement of laws and treaties.