Family in despair

The father-of-two – who was due to be married in just a few weeks' time – went missing while he and a friend were picking whelks in the Mill Bay area on Saturday.

Since then, an extensive search operation has been carried out, involving RNLI volunteers and PSNI diving crews, as well as RAF and police helicopters.

Friends and family of Mr Nixon also have been combing the shoreline, beginning in the early hours and staying until dark in the hope of finding a trace of their loved one.

Mayor of Larne, Councillor Bobby McKee described the accident as "devastating".

"There are so many people who want to do something, but yet they feel totally helpless in a situation like this," he said.

Mr McKee described Mr Nixon as a "very bubbly young fella" and that he knew the prayers of many people are with the missing man's friends and family.

"I hope they can get some comfort in the middle of this dreadful situation," he said.

Inspector Noel Rogan of Larne PSNI urged the public to leave the search those trained in such situations.

"While we are appreciative of the number of volunteers who have arrived to assist in the operation we are asking that the search be left to the emergency services and those who are specially trained for this type of work," he said.

"The conditions around the shoreline are particularly difficult with treacherous mud flats when the tide moves out. This area floods quickly and can reach four meters in places. It is therefore not advisable for anyone who is not properly trained or equipped to venture out at this time.

"We know that Mr Nixon was wearing a dark hooded top and shellsuit type trousers underneath blue waterproof trousers. Two sacks carrying whelks, similar to those used to carry coal, were also on board the boat. Should anyone come across these items we ask that they contact police or a member of the search team immediately.

A mobile police station will be set up at Magheramorne to assist with enquiries and to offer advice to volunteers who continue to arrive.

"Mr Nixon's family are being kept fully up-to-date on what is happening with the search operation and ask for privacy at this difficult time. All efforts are being made to find Graeme and I would like to thank everyone who has contributed towards the search so far," said Inspector Rogan.