Channel Islands, California
California's Channel Islands sit off the coast of Santa Barbara, just north of Los Angeles. This is one of the most wildlife-rich stretches of water on the West Coast. The ocean around this eight-island archipelago is home to a number of unique species, including sea lions and dolphins, huge sea bass (some weighing hundreds of pounds), and giant eels. Expansive kelp forests (pictured) provide an unusual setting for diving.
Five of the eight Channel Islands are part of the Channel Islands National Park and Marine Sanctuary. This is a year-round dive destination, though waters can get as cold as 50 degrees during the wintertime, so a heavy wet suit is in order. Some dive outfitters even use large yachts to bring divers on multi-day trips as they explore the islands' underwater landscapes in depth.