RedactedNarrative: On 08/24/2014 at approximately 19:10 hours a yellow 24'' Ultra had engine overheating issues and was originally stranded East of the Narrows in the Virgin Basin of Lake Mead National Recreation Area. The vessel attempted to make its way back to Callville Bay at approximately 21:40 hours. The vessel was only able to run for approximately 10 minutes before the engine would start to overheat and have to shut off. The operator was not familiar with the north section of Boulder Basin, especially at night. The vessel hugged the Nevada shoreline coming around Callville Point as it was heading back to Callville Bay. At approximately 22:15 hours the vessel ran aground on to a small outcropping of rocks associated with a submerged island. The operator and one of the passengers attempted to deboard the vessel and attempt to push the boat off the submerged rock outcropping from a larger rock that came out from the water. Efforts to push the vessel off the rocks were ineffective. Park Rangers arrived at approximately 22:21 hours. All passengers deboarded the vessel and onto the large rock sticking out of the water. Wind speed and wave action started to increase which dislodged the vessel from the outcropping of rocks and made it free floating.  Park Rangers secured all 7 passengers, the vessel, and towed it to Callville Bay. No injuries were reported.