Santa Catalina Island (Los Angeles): If it’s more about the journey for you, skip the ferry out of Marina del Rey or San Pedro and instead sail to the island. Most people do this as an overnight sailing trip, choosing to go either to Avalon, the main harbor, with the casino built by William Wrigley Jr.; or to Two Harbors, a quieter spot.
Gray whale cruising (San Diego): Been there, done that with whale-gazing from a diesel-powered tour boat? Try coasting silently on a 40-foot catamaran. Charter out of Shelter Island or other San Diego marinas from roughly December through April.
Coronado Islands (San Diego): Plan an all-day adventure into Mexican waters: The Coronado Islands, a wildlife refuge popular as a fishing and diving destination, are about 20 miles south of San Diego Harbor and about 8 miles off the Baja Coast. Aside from the scenery—sea lions, harbor seals, blue-footed boobies, and a spectacular natural archway called the Keyhole—you’ll pass Smuggler’s Cove, an old hideout of Prohibition-era boozers and gamblers.