"The men did not have the right equipment, had not done something as simple as checking the weather forecast, and they had been drinking. This was an avoidable tragedy," Mr van der Splinter said.
"Had they been wearing lifejackets, it is less likely that the tragic consequences would have eventuated. If they had carried an emergency beacon or a waterproof VHF radio it would have allowed them to raise the alarm immediately.
"Boaties have to realise that someone - the owner or the skipper - must be responsible for the safety of people onboard.
"They are the ones who must make sure the boat is operated safely. They are accountable."
Batchelor was convicted in June of permitting a boat to be operated in a manner causing unnecessary risk to the occupants.
His sentencing comes a fortnight after five boating mishaps were reported over a single weekend, including one on Wellington harbour in which a man not wearing a lifejacket drowned after the dinghy he was in capsized.
On July 1 2011, Environment Canterbury introduced a bylaw making it mandatory for lifejackets to be worn at all times on vessels under 6m long. Similar bylaws are in place for Hawke's Bay, Greater Wellington and Waikato regional councils, Queenstown Lakes District Council and Environment Southland.