One of the party, a 25-year-old woman, was taken to Edinburgh Royal Infirmary to be treated for hypothermia, but it is understood that was a precautionary measure.
She had fallen into the water and soaked through in freezing conditions.
After attempting to wade ashore the three, all in their 20s, returned to the island to summon help. The incident took place at around 1pm yesterday when the tide came in fast.
An injured seal pup stranded on a river island was brought to safety by firefighters in a dramatic New Year's Day rescue.
The starving animal – named Bodach by carers – was trapped on the isle in Musselburgh. Two Lothian and Borders firefighters waded into the water to carry the four-week-old ashore.