People living near Central Otago's Blue Lake Otago believe it could be time to ban boats from the lake after a 12-year-old boy died.
The boy fell off a sea biscuit on Boxing Day and was then stuck by another boat.
The Otago Regional Council changed the rules several years ago regarding how fast boats could go on the lake.
But local resident Lorraine Bennett told Summer Report the lake had become increasingly busy.
"The feeling is amongst many people here, particularly people who use the lake, who swim, that the boats probably eventually should be banned, because the lake is just so small and it's so narrow."
Ms Bennett said there was a specific area set aside for swimming but swimmers did not always stick to it.
Maritime New Zealand spokesman Steve Rendle said a million boats headed out on to the water at this time of year, and he urged all boaties to take care.
"It's very important that people, when operating boats, are aware that there may be people in the water," he said.
"They need to keep their speeds down, particularly around swimmers, and they need to be aware that things can go wrong pretty quickly.
"So the need to keep a lookout at all times is imperative."
An investigation into what happened was under way, Mr Rendle said.