A speedboat driven by a St Mary’s man which killed his friend in a collision took off like “a skier hitting a ski jump” because of its high speed, a court has heard.

Philip Colver, 32, has pleaded not guilty to the manslaughter of 31-year-old Benjamin Cochrane, who died when the vessel crashed into his fishing boat off St Mawes on July 16 2005.

He also denied causing grievous bodily harm to Ben’s brother Frazer and friend Chay Richardson, who were also in Cochrane’s 15ft Dory.

He admitted breaching marine regulations by failing to keep a proper watch, driving at excess speed and failing to exhibit navigational lights.

Prosecution witness Anthony Heslop of the Maritime and Coastguard Agency (MCA), said: “When it hit the Ketts (Mr Cochrane’s boat) it had the effect of a skier hitting a ski jump - there was very little damage to the Ketts.

“I conclude that Carrie Kate (Colver’s boat) would have been going at very close to its absolute full speed to clear the Ketts. That speed would be approximately 30 knots (35mph)”.

He said he doubted the Carrie Kate could have cleared the Ketts at 25 knots.

MCA marine surveyor Capt Roderick Johnson told the court he considered 8-10 knots a suitable speed for the water between Falmouth and St Mawes where the collision took place, but with lights on.

The Ketts did not have any lights and the Carrie Kate’s were not switched on, Truro Crown Court was told.

On Tuesday the jury visited the scene of the accident at St Mawes.

The eight men and four women, along with judge Mr Justice Owen, watched from St Mawes Castle as a speedboat similar to the Carrie Kate came across the water.

They then returned to court to hear evidence from two passengers who were in Colver’s boat.

Ciaron Gray, who was in the boat with girlfriend Alison Jenkin and her friend Rosanna Martin, said Colver “was not drunk and did not appear to be affected by the alcohol he had consumed. I had no concerns about his ability to control the boat or about travelling quite fast.”

Rosanna Martin said Colver did not strike her as being drunk.

On Monday, prosecutor Philip Mott QC had told the jury that both Colver and Cochrane had been drinking and were more than twice the legal drink-driving limit when the crash happened.

The pair had been drinking together in a pub in Falmouth earlier in the day.

“The allegation against Colver is not that he was negligent, he is charged with being so grossly negligent that his crime is categorised as manslaughter,” he said.

The trial continues.