It's fine to book the following trips after you get to London. Simply call for availability and directions; included are phone numbers from inside London.

REGENT'S CANAL BOATS

— London Waterbus, April 1-Sept. 30, from Camden Lock and Little Venice. Round-trip is 7 ($13) and one way is 5.50 ($10). Also stops at London Zoo. 020-7482-2660; www.londonwaterbus.com.

— Jason's Canal Boat Trip, round-trip or one way from Little Venice and Camden Lock April 1- Nov. 6. Round-trip is 7 ($13) and one way is 6 ($11). 020-7286-3428; www.jasons.co.uk.

— Jenny Wren, round-trip from Walker's Quay near Camden Lock, April-October and winter as permitting. Round-trip is 7 ($13); also has lunch and dinner cruises. 020-7485-4433; www.walkersquay.com.

— Also see the London Canal Museum at Camden Lock for a history of the canals, www.canalmuseum.org.uk.

BOATING IN HYDE PARK

Rent "pedalos" (pedal boats) and rowboats June-September on the Serpentine Lake; 5 ($9) per hour; 2 ($3.50) 12-under. Nearest tube stop is Knightsbridge. Hours 9 a.m.-6:30 p.m.; 020-7262-1330. www.royalparks.gov.uk/parks/hyde—park. Regent's Park also has boating.

CRUISE THE RIVER THAMES

— Bateaux London and Catamaran cruises: Lunch or dinner, sightseeing, and hop-on, hop-off cruises that let you stop at various locations. From 8 ($14). 020-7925-2215, www.bateauxlondon.com.

—Thames Clippers fast commuter ferry. Its hop-on, hop-off service called River Roamer is 7 ($13). 087-0781-5049, www.thamesclippers.com.

— City Cruises: Lunch, tea and dinner, sightseeing, and hop-on, hop-off cruises. From 9 ($16); also offers the London Showboat dinner cruise from 58 ($96). 020-77400-400, www.citycruises.com.

— London Duck Tours: Land and river tours in duck-mobile. From 17.50 ($33). 020-7928-3132, www.londonducktours.co.uk.

— Westminster Passenger Service: Takes you all the way from Westminster to Kew Gardens or Hampton Court. A round-trip to Kew is 16.50 ($30) and takes 1 to 1 1/2 hours depending on tides. 020-7930-2062, www.wpsa.co.uk.

— Thames Luxury Charters: Collect all your friends and rent the entire Elizabethan riverboat (capacity 250) for 440 per hour (minimum 3 hours for a daytime cruise Monday-Friday. Prices higher on weekends). 020-8780-1562, www.thamesluxurycharters.co.uk.