One person is in serious condition in Tauranga Hospital after being rescued from the water at the Tauranga Harbour entrance overnight.

A 4m boat struck something in the entrance around 11pm and St John Ambulance and police were alerted by a member of the public.

Two people were rescued from Tauranga Harbour and one person was taken to hospital. File Photo.

A St John Ambulance spokesperson says it is still not clear what the boat hit whether it was rocks or something floating in the water.

'Two people were rescued from the water. One was taken to Tauranga Hospital in moderate to serious condition and the other person was not injured.

'Although we don't know what they hit, we know it made a hell of a thud.”

Coastguard Tauranga were on standby but were not directly involved in the rescue operation.

Operations manager Simon Barker says they handed the patient to St John Ambulance and that was it.

'The people were rescued by members of the public. We weren't directly involved in it.”