According to Department of Marine Resources, the boat caught fire near Horn Island. Melissa Scallan with DMR says a boat from the National Parks Service also responded to the call and helped remove the boaters from the watercraft.
Two boats from DMR are on the scene, as well as Biloxi Fire Department.
Witnesses say heavy black smoke could be seen pouring from the watercraft and authorities had a large section of the water surrounding the boat cordoned off, preventing anyone from getting too close.
Officials say the 40 foot sport fishing boat sank once the fire was extinguished. It is not known at this time what caused the fire, or if there were any injuries.