Auckland's freediving club wants Aucklanders to join them at Lake Pupuke to raise awareness about safety on the water today.

A spate of summer drownings, including those of two experienced freedivers at Great Barrier Island last month, has raised concern in the community.

There's 50 people registered for the safety day but Auckland freediving spokesman Rob Harrison says he wants to see double that on the water.

He says they're hosting in and out of the water presentations and will be teaching the core skills that people need to make sure they 'come home from a dive.'