THE teenager who sustained a serious head injury when a £1million powerboat flipped over and crashed has been transfered to a London hospital for further treatment.

Simon Dredge was travelling aboard a Vector powerboat prototype on a scheduled test run when it struck a buoy yesterday on Southampton Water shortly after 8am.

Southampton General Hospital has confirmed this afternoon that the 17-year-old has been transferred to Guy’s and St Thomas’ Hospital in London.

As reported, he was with his father, company director Peter Dredge, 52, (pictured below) who may have risked his own life to save his son who was unable to escape the cabin as it filled with water.

Daily Echo:

One of the inshore lifeboat team who rushed to their aid described how Mr Dredge returned to the upturned boat when he didn't emerge.

Today Simon is said to be in a “stable condition” in Southampton General Hospital after he was initially taken there with life threatening injuries.

Daily Echo:

All the four-man crew were injured.

A statement released by the company today said: “The boat was piloted by highly experienced powerboat professional Peter Dredge and was carrying three crew members.

"All were admitted to a local hospital for observation. Three of the crew have now been discharged, the fourth remains in hospital in a stable condition pending further treatment.”

A spokeswoman also confirmed the model was a Vector V40R powerboat prototype.

Onlookers witnessed the dramatic crash which was captured on camera by photographer Daniel Ubertini, 66.

The 40ft-long prototype, said to be worth around £1million, is new to the company's range where similar vessels are said to reach speeds up to 138mph.

Mark Weatherhead, part of the Calshot RNLI inshore crew who rescued those on board, described the individual thought to be Mr Dredge as a 'hero' by pulling him from the boat.

He said: "They managed to open the cabin door and three of them got out and onto the work boat.

"The fourth person wasn't seen so he went back into the boat and pulled the fourth crew member out.

"It was brave going back into an upturned boat when you have opened the cabin door up to get out. There's the potential that it could sink at any time.

"Potentially by doing what he did he saved the fourth crew member's life. Getting out of a vessel is hard enough in itself.

"To go back in and get somebody out - I think he did a fantastic job.

"It was a pretty heroic thing to do. He obviously risked his own life to do it."

Mr Dredge is the founder and chief technical officer of Vector World who design and manufacture powerboats and has been a competitive powerboat racer for over 30 years.

He also held the post of Director of Powerboat Racing and Recreational Motor-boating at the Royal Yachting Association (RYA) for 14 years.

He was responsible for developing many of the safety standards and guidelines used today, in all aspects of recreational and professional powerboat racing.

He has won two World and three European Championships and has broken 21 World Speed and Endurance Records, 15 of which still stand today.

Mr Ubertini, who was out taking photos of the powerboat prototype, saw the craft flip near the entrance to Hamble Marina, Hants, this morning.

He said: "This morning was a perfect day to take some pictures and do some tests on the speed boat.

"The boat came in after going around Southampton, Gosport and the Isle of Wight and he was on his way back when he turned at the end of the Hamble river.

"He hit a bouy and he flipped on there. Within 15 or 20 minutes the boat was surrounded by about six other boats helping the injured."

Mr Ubertini, a yacht valeter at Hamble Point Yacht Charters, said people began making frantic calls to the emergency services.

He added: "The sea was flat, it was perfectly flat and he was trying his boat out because the water was perfect.

"The bouy was very close and he hit it on the port (left) side."

Two RNLI lifeboats from Calshot along with several ambulances, a Coastguard helicopter and the police marine unit tended to the four men at the scene.

Another man in his 50s and a man in his 20s were also injured in the crash and all the men were taken to Southampton General Hospital, by ambulance.

A Coastguard spokesman said: "Just after 8 am this morning UK Coastguard received multiple 999 calls from members of the public reporting that a speedboat had crashed into a cardinal marker and capsized, just outside the Hamble River, close to the Warsash Maritime Academy.

"The Coastguard requested the Search and Rescue helicopter from Lee-on-Solent to the scene along with both RNLI lifeboats from Calshot.

"The speedboat had four people on board. All four have sustained injuries."

James Way, Maritime Operations Controller for the Coastguard, said: "Our rescue assets were on scene quickly.

"All four people were transferred by lifeboat to the shore, they are all being taken to Southampton General hospital by road ambulance.

"The Police and the Marine Accident Investigation Branch have been informed."

David Griffiths, from the South Central Ambulance Service, confirmed that the teenager on board was left with life threatening injuries.

Eye witness Gary Pullen, an aircraft electrician, heard the crash while out jogging over his headphones.

The 33-year-old, from Warsash, Hants, called 999 as he was just 800 metres from the crash and said: "I was the closest one to the crash.

"The noise was something else, it was so loud that I could hear it over my headphones.

"It was just tanking it up and down the water, like it was full on flying across the water.

"It looked like it was trying to go around the buoy, but obviously it hit it and went flying into the air. It was a spectacular crash, but it was chaotic.

"It wasn't until after a couple of minutes I saw someone's arm waving back at me from the water."

Daily Echo: The upturned boat in The Solent, near the harbour at Warsash.

A statement from Vector powerboats today confirmed one of their £1million prototypes crashed in the Solent on a scheduled test run.

It read: "We would like to confirm that a Vector prototype powerboat was involved in an incident on the Solent today, 13th May 2015.

"The boat was piloted by an experienced professional and was on a scheduled test run.

"The crew were admitted to a local hospital for tests and observation. We wish them a speedy recovery."

The range of Vector powerboats can travel in speeds from 40 knots - or 46mph - up to 120 knots - or 138mph.

It has a renowned pedigree in racing with almost 30 years experience in manufacturing and racing.

This year its boats are due to feature at the Goodwood Festival of Speed and at a Top Gear Cannes Festival shoot.