On Rick's radio show some London guides were talking about fun ways to spend a long layover at LHR, and they mentioned that a cool thing to do is take an express to Paddington and very close to the station is a boat quay for the canal, where you can float up through Regent's Park and to Camden market and then come back, and return to LHR - all easily bob's-your-uncle done.
Does anyone know the details of getting on the boat? The agencies listed on google maps are well over £100 for 2 hours or are for an entire barge -- what retailer can a solo or couple use, and where are they located near Paddington Station? TIA