Rock anglers are being urged to wear life jackets to prevent more deaths as authorities expect more people to take to the water over the Easter weekend.

Rock fishing is a popular recreation activity in Australia and New Zealand but is considered dangerous as waves can sweep those fishing on the rocky outcrops away from shore.

Among the 30 people killed in the ocean off New South Wales during the 2013-2014 financial year, rock fishing was the leading cause of death, accounting for eight fatalities.

None of those killed was wearing a life jacket.

"Generally rock fishing happens at isolated locations between patrolled areas on those busy rock platforms, which is why rock fishing is such an inherent danger," Surf Life Saving NSW's Andy Kent said.

NSW Police Assistant Commissioner Mal Lanyon said he could not stress enough the importance of wearing life jackets.

"Due to the unpredictability of tides and waves you can't be certain of the conditions you're going to face when you're out rock fishing," he said.

"We are expecting to see lots of anglers out this weekend, and while the current weather predictions are suitable, it can change at any moment."

The national manager of marine weather services at the Bureau of Meteorology (BOM), Neal Moodie, urged rock fishers to check the wind, wave and tide conditions to find the safest location or to change plans.

"The ocean can be an unpredictable and deceptive environment at times," he said.

The 10-year coastal drowning average is 38 to 39 people per year in NSW.

According to the BOM, autumn is the peak season for hazardous surf conditions, with tidal heights increasing.