The pilot, who is a long-standing member of the flying club at White Waltham, had landed on Runway 21 and intended to taxi to the fuel pumps to refuel. Because forward visibility when taxiing is limited on the Extra 300, the pilot adopted a weaving path to clear himself from other aircraft and to follow some existing tyre tracks. Unfortunately, he did not see a small, low bowser containing Jet A1 fuel which the aircraft struck nose-first, causing damage to both. The pilot admitted that he had known perfectly well that the bowser, which is almost always parked in that location to service helicopters, would be there but on this occasion he had not picked it up visually. He was of the opinion that conflict was more probable with aircraft landing on Runway 21, since the bowser is located along the path that such aircraft would be likely to use when taxiing to the fuel pumps.