Europe's major metro areas have come up with some splashy ways to sightsee (and beat the traffic) that are just as enjoyable in the winter as they are in the summer.

LONDON The Tate to Tate boat (44-207/887-8888;; $7.50 for a day pass) takes art lovers on an 18-minute journey across the Thames, from the Tate Britain to the Tate Modern, with a stop at the London Eye and the Saatchi Gallery. The catamaran—covered in bad-boy artist Damien Hirst's trademark colorful dots—leaves from the Millbank Pier.

ROME After removing 38 tons of trash from the Tiber River, the Battelli di Roma Boat Service (39-06/6789361;; $1.15 each way, $3 for a day pass) gassed up its fleetof ferries and is now shuttling residents and tourists to eight docks along the waterfront. The company recently added a Circle Line-type tour of Rome, as well as a five-course dinner cruise.

ROTTERDAM The 11 motorboats run by Watertaxi Rotterdam (31-10/403-0303;; rates based on distance) can pick you up and drop you off at any of the 33 (and counting) floating docks along the city's rivers and canals. "Rotterdam wants to be just like Venice," says manager Han Verhagen. Seems like other cities in the European Union do, too.
—Elena Bowes