There are growing concerns among competitors in the America's Cup Jubilee that the race courses set that week may lead to problems on the start line.

According to Jock Wishart, who will be helming the 12-metre boat Freedom, the new arrangements could lead to collisions with either end of the Royal Yacht Squadron start line set to be congested.

"I'm saddened that some of the 12-metre racing should be round the cans but because of class rules, they have to be windward-leeward courses which I'm sure the competitors will become bored with," he said.

"I'm also very disturbed by the start of the round the island race because I think potentially we have quite a dangerous situation. For 30 years, we have used the flashing lights on the start line but this time, they will use a committee boat in the direction of West Bramble.

"They have done a risk assessment and have decided that in an increasingly litigious society, they do not want 55,000lb lead buoys anywhere near the boats so they want to give them as even a start as possible.

"But it will be impossible to get a transit to the line so all the boats will bunch up at either end which will cause problems."