The current record of 317mph (510km/h) was achieved by Australian Ken Warby in the Spirit of Australia in 1978.
His son Dave Warby is also vying to beat the speed record with his craft, Spirit of Australia II.
Mr Aldred said he welcomed the competition but stressed “safety is paramount”.
“You can get into a situation where you are under pressure from sponsors and the public and everybody else to just get on with it,” he said.
“Campbell killed himself and the last two attempts since Ken Warby got the record have both been fatal.
“You find a problem and go away and sort it out. There’s always another day.”
A date for the Longbow world water speed record attempt is yet to be set.