Surrounded by water on three sides, San Francisco has plenty of opportunities for kayaking enthusiasts of all levels. City Kayak (Pier 39, Embarcadero at Stockton St., Fisherman's Wharf. www.citykayak.com), the only kayak-rental outfit in the city, operates bay tours along the waterfront and beneath the Bay Bridge starting from $50; they also run full-moon night paddles and trips to Alcatraz. Rentals are $15 per hour for a single; $25 for a double; and $50 for a four-person kayak. Half-day trips depart at 10 AM daily. No prior experience is necessary, but you must watch an instructional video. The Pier 39 location is for tours only, not rentals. Trips run by Outdoors Unlimited Cooperative Adventures (500 Parnassus Ave., at 3rd Ave., Inner Sunset. 415/476-2078. www.outdoors.ucsf.edu) originate in either Sausalito or Mission Bay in San Francisco and range from moonlight paddles from Sausalito (with views of the San Francisco skyline) to daytime sea-kayaking classes for all levels. Sea Trek Kayaking (415/488-1000. www.seatrekkayak.com) has trips around Angel Island and the Golden Gate Bridge, moonlight paddles, and many trips in Marin County. Three-hour trips are $65-$75 and full-day trips are $85-$95. Most excursions leave from Sausalito but Angel Island tours leave from the island.