I recently spent an exhilarating afternoon speeding up and down the Thames, courtesy of London RIB Voyages. The 'Break the Barrier' ride starts at St Katharine’s Pier by Tower Bridge and takes you to the Thames Barrier and back at 40mph. My cheeks hurt not only from being whipped by the wind (oh God, my hair) but from smiling so much. SUCH good fun.
We were given waterproofs and lifejackets before boarding the 'Thames Rocket' 12m fibreglass RIB (which stands for rigid inflatable boat, FYI) along with ten other passengers, a skipper and a host (Stacey was hilarious) and set off east. The thrilling 20 mile boat ride along the new 'Thames High Speed Zone' takes 40 minutes, as you race past the old docks, the Cutty Sark, the O2 and the Old Royal Naval College at Greenwich before turning around at the flood barrier to the sounds of a 'Best of British' soundtrack from Big Ben chimes to The Clash, Spice Girls and The Beatles.
There are a few rib tour providers in the capital, but Thames RIB Voyages is the best - they were the first speedboat operator on the Thames, first running trips back in 2006, have been awarded 5 stars by Time Out and voted number 1 activity in London on TripAdvisor. High praise indeed.
If you have a visiting nephew, grew up sailing, are a water baby or adrenaline junkie, or just fancy doing something different in London, you'll love it - I'm heartily recommending to thrill-seeking tourists AND Londoners.