Instead, with the machine “bouncing off the water in a way not previously seen as its dynamic stability broke down”, he argues the engine had cut out on the approach to the measured kilometre, causing deceleration and a loss of downward pressure.
Sheppard, who will be appearing at the Coniston Institute on Monday alongside his co-author Dr Keith Mitchell, explains: “It’s like jamming on the brakes. “But with a jetboat and the centre of gravity as it was, jamming on the brakes doesn’t push the nose down, it does the opposite.
“So even though it was slowing down, the boat was going to take off.
“Campbell was past the point of no return. There was nothing he could do.”
When Bluebird is lowered back into Coniston Water, Robinson, now 81, is hoping to once again be out in a support boat.
He is confident it will be “something special” and a fitting tribute to his friend.
What, though, of the future?
“In terms of running, my own view is that this should be a one-off,” he says.
“People will be able to see and hear this great record-breaker over the next few days, but then I think Bluebird should enjoy a well-earned retirement.”
