Two people have been forced to abandon a burning boat in Tasman Bay this afternoon.

Emergency services were alerted to the fire just after 1.00PM.

A rescue helicopter, Coastguard and nearby vessels responded to a call for assistance from the boat in distress offshore from Delaware Bay, about 10 kilometres north of Nelson city.

Details are sketchy but it is understood the two people aboard managed to scramble into a dinghy to escape the flames.