A man is dead after going on a crayfishing trip.

Akaroa Police said the 54 year-old Christchurch man was the only diver among a group of four people on a boat near Whakamoa Reef off the Banks Peninsula yesterday.

The man found himself in trouble and his companions pulled him from the water at 4.30pm but he did not survive.

Akaroa Police said the man was in a well-known crayfishing spot and was an experienced diver. He and his companions were about 150m from shore when he got into trouble.

The group alerted police and the ambulance service to the emergency on their way back to Akaroa.

It was not yet known how the man died. Police said it was windy in the area at the time but there were only moderate swells.

Nobody else was injured and the man's death has been referred to the Coroner.