Recreational boat skipper has been convicted and fined after pleading guilty to a charge of causing ‘unnecessary danger' under the Maritime Transport Act.

The conviction was in relation to an incident at Raglan on December 11 last year when the boat Maurice Kyle Johnson was skippering capsized, throwing himself and two crew into the sea.

The case was taken by Waikato Regional Council as part of its maritime safety role.

"This incident could easily have resulted in three fatalities," says Waikato Regional Council regional compliance manager Patrick Lynch.

"Coastguard records indicate Mr Johnson has put in at Manu Bay 154 times previously, so he is clearly very experienced, but this incident shows that complacency can have dire results in a maritime setting.

"At the time of this incident no other vessels had, or were attempting to launch, from Manu Bay, due to the sea conditions.

"A video clip from the Surfline website clearly shows what happens next and is compelling viewing.

"While attempting to manoeuvre out of the bay the boat entered breaking surf causing the front of the boat to lift to an almost vertical position.

"One occupant was thrown from the boat at that time. The boat has then taken on a lot of water and lists side-on to the next wave and capsizes. Mr Johnson and one passenger were temporarily trapped within an air bubble in the vessel's cabin.

"Thankfully, all three occupants managed to inflate their life jackets and get back to shore.

"The vessel ended up on the rocks and was badly damaged."

Following a guilty plea by Mr Johnson, a fine of $900 was imposed by Judge Paul Geoghegan in Hamilton District Court last week.

The judge also acknowledged that Mr Johnson had made a $1000 donation to the Raglan Coastguard.