The search for a missing teenager presumed to have drowned at the mouth of the Swartkops River will continue on Friday. The 17-year-old went missing when he and two friends went swimming in the area.Justin Erasmus from the National Sea and Rescue Institute said at about 10:11 on Thursday, the Port Elizabeth duty crew were activated following reports of a drowning in progress at the river's mouth."Three local male teenagers were reported to be swimming when they were caught in rip currents. Two of the teenagers managed to get to shore and were not injured but one teenager, aged 17, disappeared under the water."Despite an extensive air, sea and shoreline search, including rescue swimmers conducting free dive search efforts, no sign of the missing teenager has been found and the police will continue with the search," Erasmus said.