The number of people who died along Britain's coast in 2013 was the highest in four years, the RNLI said as it launches a campaign calling on people to Respect the Water.
Figures show that 167 people died in water-related accidents and a further 368 were rescued by lifeguard crews after getting into difficulties.
Cold water shock, rip currents and fatigue were common factors in contributing to accidents at the coast while alcohol played a part in 28 deaths last year.
As the temperature continues to soar RNLI coastal safety manager Ross Macleod called for people to stay safe around the water.
"We really feel that that number is too high and we need to do something about it," he said.
The campaign will be launched in Brighton today by England rugby player James Haskell who said: "This is about being smart and safe when you are there."
More top news
New Tour de France time-trial record set after Australian Rohan Dennis raced into the lead during Stage one of the competition.
Fresher and cooler as we head into the second half of the weekend.
Leah Washington, 17, had to have her left leg amputated after being trapped for hours on The Smiler rollercoaster at the theme park.