Officials said a 20-foot speedboat carrying three couples from Florida and Arizona sank late Saturday afternoon apparently after taking on water in windy conditions.
Brian Sweatland with the National Park Service said in a statement the bodies of two people have been recovered: Mary Anne Taranto, of Prescott Valley, Ariz., and Katherine Prescott of St. Petersburg, Fla.
Search crews spent Sunday looking for the other two who were on board when the boat sank. As of Sunday evening, there was still no sign of Terry Michael Taranto of Prescott Valley, Ariz., and Robert Prescott of St. Petersburg, Fla.
The search is scheduled to resume Monday morning.
Two people - James and Heather Brady of St. Pete Beach, Fla. - survived and were treated for hypothermia, Sweatland said.
Sweatland did not provide the specific ages of those involved but said they were in their 50s and 60s.
The cause of the incident is under investigation. Park officials say weather is believed to have been a contributing factor.
The lake is part of Glen Canyon National Recreation Area which straddles the Utah-Arizona border.
(Copyright 2009 by The Associated Press. All Rights Reserved.)