The women, understood to be students at Aberdeen University, were caught in a rip tide after entering the water at the River Don estuary on Monday night. The trio, who were part of a six-strong party of male and female swimmers aged between 18 and 20, were suffering from mild hypothermia by the time they managed to make it back to the shore at the mouth of the River Don on the outkirts of Aberdeen. They were detained overnight at the city’s Royal Infirmary for observation. A spokesman for the Maritime and Coastguard Agency said that the incident “could have been a lot worse.” A full scale search and rescue operation - involving two helicopters, a coastguard team, two lifeboats and a fast rescue craft from North Sea service vessels - was mounted after the Aberdeen coastguard rescue team received a call from a member of the public. Ten minutes later one member of the swimming party telephoned the xoastguard to inform them that three members of the party were missing after the group had been caught in a rip tide and separated. Steve Smith, a watch officer with the Aberdeen coastguard rescue team, said: ”At 6.40pm last night we got a call from a concerned member of the public who saw the swimmers going into the water. About ten minutes after that we got a call from one of the members of the group who was concerned because the group had become separated and half of them were missing.” The Aberdeen lifeboat, which was on exercise in the area, was immediately alerted and a number of fast rescue craft from North Sea standby and supply boats, berthed in Aberdeen Bay, also joined the search, together with an Aberdeen inshore lifeboat. A Bond BP “Jigsaw” helicopter was scrambled from Aberdeen heliport alongside a Sea King helicopter that was dispatched from RAF Boulmer in Northumberland to join the rescue operation. Mr Smith said: “As the search was getting underway, the three swimmers who had been missing began to emerge onto the shore in dribs and drabs. Within 30 minutes we had managed to account for them all.” “They appear to have been members of an organised swimming club. But they were not wearing wet suits. It looks like they were wearing swimming trunks and swimming costumes - no wet suits or anything else.” Mr Smith said it had been getting dark when the party went into the water in a strong easterly wind and choppy seas. “With all the factors combined, potentially it could have been a much more serious incident,” said Mr Smith. He added: “I can’t say whether it was a good or bad decision to go into the water. But when this group went in it was not something we would recommend.” One of the male members of the swimming party, who did not wish to be named, said: “We have been coming here to swim for some time. It is a student-organised activity, but the water was a bit choppy tonight. “We got caught in the current of the river and three of the girls were swept out and couldn’t get back in, so we called the coastguard.” He continued: “It was a bit nerve-racking but everyone is safe, that’s the main thing.” One of the female swimmers said: “Of the six of us, I might have been the furthest away from the rest and it was a bit of panic as I realised I was so far out. We have gone into the water about 6pm, and at that point dusk was approaching, but we could still see pretty well. “I got myself onto the beach and started to look for the rest and was a bit worried when I could not see anyone.”