The Hazardous Surf Warning service has been launched by the Bureau of Meteorology to alert the public when conditions are dangerous for rock fishing, boating or swimming due to wave height and swells created by weather systems far off the coast.

Manager Weather Services for NSW, Jane Golding, said a driver for developing the Hazardous Surf Warning was to reduce rock fishing injuries and deaths.

"A key finding from our research is that awareness of large and powerful wave conditions would influence over 90 per cent of rock fishers to change their plans," Ms Golding said.

"Boaters and swimmers also need to keep up with the latest warnings and forecasts because conditions on the water can be more dangerous than they appear, even when it seems calm and the sun is shining.

"These new warnings will help people make informed decisions about how and when they enjoy the coastal environment.”

The warnings will identify which coastal waters areas are affected and include safety advice that has been developed with maritime agencies.

NSW Police Marine Area Commander, Superintendent Mark Hutchings, said the key to water safety is assessing the environment and taking simple precautions.

“I urge anyone planning to head out onto or near the water to heed our advice – we aren’t trying to spoil anyone’s fun, we are trying to save your life,” Supt Hutchings said.

“For those out boating or rock fishing, please remember the most important piece of safety equipment is a life jacket.”

Surf Life Saving NSW chief operating officer Adam Weir said the new system of surf warnings will be a big asset to lifesavers in alerting the public to hazardous conditions.

"To be able to better target our safety messaging to the public will help us to focus our lifesaving efforts where they are needed most," he said.

The new Bureau of Meteorology service complements the current suite of coastal warnings, including hazardous surf caution messages in coastal waters forecasts (and certain town and district forecasts) and Damaging/Dangerous Surf Warnings which alert communities to significant waves that can damage coastal infrastructure.

This service will be provided in the coastal waters areas of NSW and southern Queensland. The warning will be available from the bureau's website homepage, via the National Warnings Summary:www.bom.gov.au/australia/warnings, as well as the NSW and Queensland State warning pages, marine radio, the Bureau App, and mobile website.