If you think Los Cabos scenery is stunning, wait until you see it from the bottom up. In Cabo San Lucas, underwater beauty is close by, and experiencing it is easy to arrange. A protected marine sanctuary, Cabo San Lucas Bay shelters schools of tropical fish, sea lions, and exotic marine life. Spear fishing, collecting, and fishing is illegal but exploring has no limits. Snorkel tours leave from Playa El Médano across the bay, or you can book through your hotel's activities desk. For the less experienced diver, try Pelican Rock, Neptune's Finger, or the Sea Lion Colony. Advanced divers shouldn’t miss the stunning and challenging Abyss (Middle Wall), or the Sandfalls (a 90-foot dive documented by the late Jacques Yves Cousteau), which begins at Pelican Rock then drops to an incredible 1,200 feet. Cabo Acuadeportes, Land's End Divers, Ocean SCUBA Cabo, Underwater Diversions, Tio Sports, and Nomadas de Baja are a few reputable and experienced shops who can take you there and to other dive sites.

The bay side of the arch area is a prime location for SCUBA diving. Visibility ranges from 30 to 60 feet in winter and spring to over 80 feet from July to November. Try a two-hour guided snorkeling tour, or rent gear at dive shops around the marina and take a water-taxi to Lover’s Beach, near El Arco, to swim, snorkel, dive, and watch the sea lions.