Test the clubbing waters

A chap in a home-made white cardboard top hat is dancing slightly strangely in one direction, and a gaggle of tipsy revellers are gently swaying on the outside deck in the other. A bassy remix of Muse's epic track Knights Of Cydonia thunders from the speakers as we pass under London Bridge, illuminated in bright neon orange and pink.

It's a surreal end to a majestic musical voyage along the Thames. The journey began some four hours earlier at Embankment Pier as we boarded the pleasure cruiser Viscountess.

River trips have traditionally been a more serene proposition than this, involving tea and cake, or maybe a swing band and pints of mild for the more adventurous. And yes, boat parties have long been thought a bit naff, suitable only for the hen/stag crowd or office outings. Moreover, following the 1989 Marchioness dis-aster in which 51 people died, there have been understandable safety concerns.

But in the 18 years since, much stricter safety regulations have been implemented, and boat parties have slowly regained popularity. Now super-cool promoters are holding intimate bashes on-board, making for great nights out.

Our particular maritime knees-up is the work of Supatronix, a group of London-based DJs who have a residency at The Medicine Bar in Shoreditch and specialise in breakbeat, a dirtier, funkier, slowed-down version of drum&bass.

They've chartered this vessel and loaded on decks, DJs and a sound system. For £20, the ticket includes an after-party back at The Medicine Bar. The only snag is that you can't be late - or you'll find the ship has sailed without you.

On this early Saturday evening the sun is shining down from a cloudless sky as we steam off east in the afternoon heat. The relaxed vibe mingles with anticipation - for the journey and the music alike.

Boat parties such as this are gradually becoming a summer fixture. Buttoned Down Disco ran an indie night on a boat recently, while New Yorkers Turntables On The Hudson are having a hip hop cruise on 18 August, and tonight Acid On Sea is holding its own boat rave-up.

Supatronix ran one back in June and it proved such a success that they're doing this event as an encore.

The Thames is a beautiful place for a party, with all the riverside scenery and London landmarks flashing past you, the sun and the water. The boat is small - holding only 200 people on two levels - but perfectly formed: there are outdoor decks at either end to mill about on, a dance floor in the middle and a bar with a limited but perfectly acceptable range of drinks.

Cold beers in hand (Becks, £3.50, Carlsberg, £3), we cock an ear to the music but our attention is mostly focused on the wonderful views of the city, folding out from the river.