The Selsey Coastguard team were called out to a fire onboard a boat at Medmerry Nature Reserve late on Thursday evening.
Other emergency services were in attendance, along with Counter Pollution officers and the RSPB who manage the reserve.
The coastguard were called earlier in the day to the boat washed up on the beach and no one on board.
The team say the boat was set alight by it's owner
Due to its remote location the Fire service advised it was best it was left to burn out.
A spokesperson for the Selsey Coastguard Rescue Team has advised citizens to 'steer clear and keep dogs on leads if walking on the beach at the Medmerry Nature Reserve, due to lots of debris which still remains, until the beach is cleared."