RedactedNarrative: On Sunday, May 24, 2015, vessel owner reported that Vessel A backfired while underway and then the engine compartment caught fire leading to total loss of the vessel due to the fire engulfing the vessel. The vessel later sank to the bottom of Elephant Butte Lake. The vessel owner attempted to extinguish the fire with onboard fire extinguishers to no avail. Owner/operator and passenger were wearing their PFD's, entered the water to escape the fire and were picked up by a nearby boater safely.