A marine engineer who showed Stephen McKinney, the father of two accused of drugging and dumping his wife off a holiday cruiser, how to operate the pleasure boat, today (Friday) admitted ticking the boat's safety check list to show it had four life jackets.

The engineer from the Manor House Marina and Cottages Ltd, said he'd filled out the 'boat acceptance certificate' the following morning after hearing that 35-year-old Lu Na McKinney had drowned on Fermanagh's Lower Lough Erne.

Mr. McKinney's Dungannon Crown Court trial has already heard him described as a killer controlling husband, tired of his wife he feared divorcing him, and that Lu Na's death in the early hours of April 13, 2017, was "no tragic accident".

The 43-year-old, originally from Strabane, but who lived with his wife and children in Flaxfield, Convoy, Co Donegal, and now has an address in Castletown Square, Fintona, Co Tyrone, denies murdering his wife.

Under cross-examination by defence QC Martin O'Rourke, the engineer who accepted he held no qualifications to give tuition on handling cruisers, said that Mr. McKinney should have had the form and to tick off each item on the check list as he was instructed on it.

Telling the court, he "thought it was my fault something had happened", he initially got the check list to see if there was "anything I could have done better ... a girl had just died".

And the more he "thought about it" he realised there were only two life jackets onboard the cruiser, but that he had "advised Stephen" to go and collect two more, for the children, from the marina reception, and thought they had done so.

Although the engineer accepted he had ticked the box showing the boat had four life jackets, he denied falsifying the document, and claimed, "this was just me being stupid", and that the form had "nothing to do with the woman's death".

"It was just my own stupidity I was doing it,"  said the engineer who accepted that it was his responsibility to ensure there was an adequate number of jackets onboard, and that he had dated the form, April 12, when the McKinney family took out the cruiser.

Although at one stage he said he'd filled out the form after "panicking", he later added it had no legal status, and "was worth nothing" because it wasn't signed.  However, he denied creating the form as part of "a cover-up" and only after police came looking for it as part of their investigation.

Earlier in his evidence he told prosecution QC Richard Weir that he's advised Mr. McKinney not to moor overnight on an island as it would be harder to reach them in an emergency or if the boat broke down.

He also said he had told him to avoid the west jetty on Devenish Island as there was a mucky path to the historic site and that there would be more shelter on the east side of the island.

Asked about his capabilities in handling the cruiser, the engineer sad that Mr. McKinney had been “okay driving the boat”.  He also told the jury that while demonstrating the workings of the boat, Mrs. McKinney paid little interest and sat reading a newspaper.

He said the following morning when he went to collect the cruiser from Devenish, it would not start, and had to be towed back to the marina.  However, once back at the Manor House, "it was a relatively minor repair" to get it working again.

The trial continues on Monday.