The vessel, Last Call, was sunk by huge waves at the mouth of the harbour last November.

Andrew Carrick (45), his brother John (36) and Andrew’s partner of 26 years, Jill Russell (48) died after plunging into the freezing North Sea.

A Marine Accident Investigation Branch (MAIB) report has laid much of the blame on a lack of seamanship, coupled with the fact the Last Call had been purchased over the internet from the United States, without going through the usual assessment to prepare her new owners to sail in her.

The MAIB report warned: “The favourable dollar/pound exchange rate has triggered an increase in the number of boats imported from America into the UK.

“Currently, inspection of these vessels at the point of entry into the UK by Trading Standards is impractical, not financially viable, or required by statute.”

The report recommends a tightening-up of import rules so new owners have their vessels properly checked and know what sort of weather they can sail in.

Referring to the Whitby accident, the MAIB said the determination of the ‘naive’ and over-confident sailors to go for one last sail in their boat – purchased second-hand through an independent American brokerage on the internet – cost them their lives.

It also highlighted a series of mistakes made by the inexperienced boaters it says could have been avoided with proper statutes governing the hand-over of boats coming into the country.

But retired architectural joiner John Carrick (78) speaking from the family home in Middlesbrough, said: “They were not stupid. They did not go out to commit suicide.

“From what I have been made to understand the conditions in the harbour were not severe. It was only when they hit the bar that suddenly they would have realised.”

He could not disagree with what the report said.

“It won’t bring my two sons and my ‘daughter-in-law’ back. This is a tragedy that I think was unforeseen and it’s cost the lives of the three of them.

“The conditions were unfortunate. You cannot blame anybody.”

As well as criticising the friends for not being properly equipped, the MAIB report has also stipulated that Whitby needs to provide more information to recreational sailors, including the impact that strong northerly winds can have on the sea.

Mr Carrick snr, who also has a daughter, Tracey, said he and his wife Margaret had nothing but praise for the actions of the local lifeboat crew and harbourmaster and port authorities.

An inquest will be resumed on 16 July in Scarborough.