It can be, especially if you're sitting on the bow locker!
But that aside, being so close to the water gives you a good sensation of speed, so it feels like you are going quicker than you actually are.
RIBs (well not all admitedly) are easily movable via a trailer and cheap to run.
For me, it was a relatively cheap and simple way to get into boating, ideal for a quick after work jaunt!
You have extra bouyancy in the event of an accident too
In the summer I'd rather head over to Turkey and indulge in a spot of sailing, as sailing a Lagoon 380 through central London isn't really an option ;-)
Having made enquries at Gallions Point, South Dock and Limehouse, it seems that all are miles away from petrol (according to Google maps, although I could have sworn there was a Texaco Garage near Limehouse). Also, all 3 have locking restrictins in the evening, albeit South Dock is the most friendly in that respect, yet has the longest waiting list :-(
Therefore I will keep trying, but does anyone know of any marinas/pontoon's further down towards Southend (yet as close to London as pos)?