They were all wearing long gumboots.
In her report, Coroner Heather McKenzie said after the dinghy capsized, all three men surfaced about the same time — almost within arm's reach of each other.
"Mr Anderson and Mr Gorton grabbed the front of the dinghy which was above the water," she said.
"Mr Anderson yelled at Mr Boniface to 'get his gear off' and he and Mr Gorton removed some of their clothing."
At this time, Boniface started to swim to the shore which was about 100m away.
It was after a witness heard a man call to Boniface to take off his gumboots that he went under the water and did not resurface.
Gorton attempted to swim to Boniface, however, the current was too strong and he lost sight of him.
Boniface was located by divers on September 12, 2018. He was fully clothed but was not wearing gumboots.
McKenzie said while Anderson stated he had consumed two beers while on the boat. There was no evidence he was affected by alcohol — there was also no evidence that the behaviour of Boniface or Gorton had caused the boat to spin.
Boniface's blood alcohol level was 116mg and there were indications of cannabis use in his system, however, there was no evidence that these affected his ability to swim to shore.
It was reasonably possible Boniface's chances of survival "would have materially increased" had he been wearing a lifejacket, McKenzie said.
She said it was reasonable to infer someone wearing gumboots which filled with water would be weighed down.
"In many circumstances, particularly where the water is over the person's head and water conditions might be challenging such as due to the current or swell, I consider it possible that it would be difficult to remove gumboots in the water."
She recommend gumboots not be worn on boats of less than 6m.
