Self-propelled pastimes: Don't forget about the quieter thrills, the ones that are powered by you, not by jet fuel or electricity. There's excitement in exploring by kayak, satisfaction in learning to paddleboard. Rent kayaks, windsurfers, paddle boats, paddleboards and surfboards at 48th Street Watersports. You can venture out on your own, go on a kayaking eco-tour searching for marine life along the shallow waters of the Bay, take a paddleboard fitness class, or learn to sail a catamaran. (48th Street Bayside, 410-524-9150, 48thstreetwatersports.com. You can also rent 1-person and 2-person kayaks at the Bahia Marina, 2107 Herring Way, 410-289-7438, bahiamarina.com. Rent kayaks, paddleboards and jet-skis at Back Bay Adventures (400 East 32nd Street. Bayside, 443-783-4633, backbayadventuresocmd.com.