It's a classic Cape Cod activity: a daytime, sunset or moonlight cruise out of Hyannis Inner Harbor to survey the grand mansions and yachts along the shore, Great Island, Egg Island, Squaw Island, Point Gammon Light and other lighthouses, to smell the salt breeze and chat with other travelers.

Bay Spirit Tours (tel 508-771-0107) operates one-hour daylight cruises, lighthouse tours and sunset cruises with its 63-foot (19-meter) catamaran Bay Spirit.

A longer 3-hour cruise-tour takes you farther into Nantucket Sound to see seals relaxing on rocks and beaches, and diving into the sea for a romp.

The Bay Spirit departs from Hyannis's Ocean Street Dock, adjoining Bismore Memorial Park, opposite the Black Cat Restaurant, and near the Hy-Line Cruises docks for ferries to Nantucket (map).

Speaking of Hy-Line Cruises (tel 508-790-0696), they also operate one-hour Hyannis harbor cruises aboard Prudence, a historic Maine 1911 coastal steamer. In fact, it was this cruise that established the company back in 1962.

Hy-Line also offers a Rail & Sail tour that includes a 2-hour scenic ride aboard the Cape Cod Central Railroad and a 1-hour harbor cruise. You pay less for the package than you would for the separate rail tour and harbor cruise, but you needn't take them together on the same day. It's a good deal.

Take your pick: a sleek, smooth, modern catamaran or a historic Maine coastal boat, but do get out on the water to see Hyannis from the water.

Reserve your place(s) in advance for either cruise, and be at the dock at least 30 minutes before cruise departure for boarding and safety instruction.