Well, maybe not actually fish, but floating bicycles are being touted as the answer to London's congestion by the Monster Raving Loony Party.
The appropriately-named 'Loony Bike' was demonstrated on Sunday by the party's very own shadow minister for big fibs and blatant lies, who believes it will be ideal not just for when London is flooded due to global warming, but for using on canals. Not enough canals in London, we hear you cry? Increase employment by building more, says Knigel Knapp.
The mayor's slightly more pedestrian alternative of a cycle superhighway received more criticism last week for not being wide enough and cleverly encompassing potholes, drain covers and other impediments to safe cycling. Boris Johnson, despite a near miss while out riding last year, is still keen to promote cycling in the capital so perhaps it's time he and Knigel Knapp got together and proposed a cycle lane on the Thames. They might have to dodge boats and piers but at least if they fall off, a thorough soaking is the worst of their worries.
Other transport proposals from the Monster Raving Loony Party include banning tractors from the roads, declaring the Channel Tunnel a no-fly zone and all-terrain hovercrafts all of which make the floating bicycle sound perfectly plausible.