Centre for Maritime Safety Director Peter Harvey is urging all boaters to take extra safety precautions when heading out on cold water this winter and beyond.

"Boating is a great pastime, but in winter there are additional risks that boaters need to be aware of," Mr Harvey said.

"Water below 15 degrees is considered dangerous but temperatures at that level and below are commonplace across NSW waterways at this time of year, and in alpine areas all year round.

"If you fall into cold water, cold shock can set in very quickly and you're at serious risk of hypothermia, or dangerously low body temperature. Wearing a lifejacket at all times can save your life."

NSW Maritime Assistant Executive Director Alex Barrell said a lifejacket helped manage the initial cold shock and conserved energy: "Try to get back onto your vessel as quickly as possible or get as much of your body out of the water as you can. Only swim for shore if it's close by and you're sure you can make it quickly."

"If you have no other choice but to stay in the water, stay with the vessel and huddle with anyone else who is in the water to reduce the loss of body heat," he said.

"If you're by yourself, retain heat by drawing your knees to your chest, wrapping your arms around your knees and clasping your hands together."

The Centre for Maritime Safety and NSW Maritime is committed to educating the NSW boating community on managing the risks associated with cold water.