The rescue team had just landed at Royal Air Force Valley in Anglesey, Wales, after another rescue when they received a call about the two teens Thursday, the BBC reported. The crew immediately took off again and arrived on the scene in about 38 seconds, co-pilot Lt. "Schmoo" Smith said.
The two girls, who were body-boarding along the Anglesey coast and had been caught in a rip tide, were described as exhausted.
"When I got to her, the elder girl was clearly exhausted and was going under the water for what was the very last time," Winchman Master Aircrew Harry Harrison said.
"We never know what we'll face when we're called out," he added. "Sometimes it's just a twisted ankle or a broken bone, but this was one rescue where we truly did arrive in the nick of time and managed to save two young lives."
The crew transported the girls to Ysbysty Gwynedd hospital in Bangor, The Mirror reported.
Prince William qualified to be a search and rescue pilot in September 2010 and was made a captain in June, The Mirror reported.