KIRKLAND, Wash. -- King County sheriff's divers are using a different type of scanning sonar Tuesday in hope of locating the body of a man presumed drowned in Lake Washington near Kirkland.

The search has been complicated by dense water weeds up to 15-feet tall.

Divers have been looking for the body of 20-year-old Javed Khan who was with friends on a boat Saturday night when he jumped in and went under the water off Juanita Beach.

Khan's father, Mohammed Feroz Khan, said he and his son were fasting at the start of the Muslim Holy Month of Ramadan. He said the fast may have made his son tire more easily.

King County divers have searched the water as well as units from Mercer Island, Kirkland, Seattle and Coast Guard also assisted.