LAS VEGAS (AP) - Authorities are investigating the sinking of a yacht owned by Las Vegas entertainer Wayne Newton at a Lake Mead marina. National Park Service spokeswoman Christie Vanover said Monday that the 65-foot vessel sank stern-first in 45 feet of water while it was in a slip at the Temple Bar marina. That's on the Arizona side of the Colorado River reservoir, about 80 miles east of Las Vegas. Vanover says no one was on the boat, and no injuries are reported. Newton's sister-in-law, Tricia McCrone, confirms that the 1996 Skipperliner named Rendezvous (RAHN'-day-voo) belongs to Newton. McCrone says Newton and his wife were vacationing out of the country when the boat sank Friday. A photo provided by the Park Service shows the boat's bow sticking straight up from the water.