RedactedNarrative: Operator of Unit 1 stated he was travelling east on Lake Moultrie when a thunder storm came up.  Operator stated that his jet ski overturned and he and his passenger could not get the jet ski back upright.  Both subjects were in the water for approx. 15 hours.  Both subjects had gas burns but only one was transported via EMS to the hospital and later to the Augusta Burn Center.