A diver had to be airlifted from Rotorua to the Davenport Naval base after suffering chest pains.
The Rotorua-based BayTrust Rescue Helicopter was called to airlift the 24-year-old about 9pm man last night.
Helicopter pilot Todd Dunham said the man was diving in Lake Rotorua with friends and held his breath while ascending, which resulted in chest pain.
"Due to the circumstances with decompression sickness, the helicopter had to fly to the coast and up to Waihi keeping as low as possible so as not to increase the sickness," Mr Dunham said.
"The hyperbaric chamber is used to reverse the effects of this illness."