One hundred lives have potentially been saved by the Water Rescue Squad, Dunedin Marine Search and Rescue adviser Rowan Leck says.
Since the squad was formed in 1994, it had attended 250 calls and assisted 100 people.
Tomorrow at 7pm at St Kilda Beach, members of the public will be able to set off distress flares to mark the 20th anniversary of the squad's formation.
The squad was formed because recreational water users were seeking more and more isolated spots for boating, fishing and surfing, Mr Leck said.
In the seas near Dunedin, where the water temperature was about 10degC, any incident could be life-threatening, he said.
''Your survival time if you go into the water is quite short.''
The squad's members were trained to be rapid response rescuers who could get to those in need quickly and get them to safety.
The rescue of the crew of Groupama, which overturned off Cape Saunders during the round-the-world yachting race in 2008, demonstrated what was envisaged when the squad was formed, he said.
