Water is the whole point of Key West — snorkeling, sailing, and fishing dominate the activity list, alongside its famous sunset cruises.
Multiple tall ships (like the Western Union and America 2.0) depart from the harbor nightly for a two-hour sunset cruise with drinks included — the classic Key West evening.
Catamaran trips out to the only living coral barrier reef in the continental US, part of the Florida Keys National Marine Sanctuary — gear, instruction, and usually a rum punch included.
A 90-minute narrated tram loop past all of Old Town's major sights — a good first-hour orientation before deciding what to revisit on foot.
Guided light-tackle fishing trips into the shallow flats around Key West for tarpon, bonefish, and permit — a bucket-list trip for anglers, no experience required.