A woman fell in a rock pool and was knocked unconscious before the annual Portrush Raft Race on Saturday.
The start of the 32nd RNLI Portrush Raft Race, in aid of the local Lifeboat Station, was delayed by 20 minutes.
The young mother fell into the pool at the West Strand beach in Kerr Street.
The woman, understood to be Polish, took water into her lungs but was quickly rescued and received treatment from the emergency services in attendance at the event.
The spectator, who was in the Co Antrim seaside town for the annual family event, which draws thousands of people to the area, had been attempting to retrieve her toddler son from the water at the time of the accident.
It's also understood she suffered a broken ankle.
Her child was injured in the incident.
"It was very scary," a local man said. "The West Strand water is very deceiving; one minute it can be a couple of inches and then a four-foot drop. The woman's child went in and she ran in after him and got into difficulty.
"She had to be revived and an ambulance took her to hospital.
"It was lucky they were there."
A Coastguard spokesman said with the 32nd RNLI Portrush Raft Race events being on throughout Saturday and Sunday, the police, ambulance service, Coastguard and St John's Ambulance were already on site.
"The woman fell and broke her ankle and fell into the rock pool," he added.
"She took on a lot of water."
A spokesman for the ambulance service said it received a report of an unconscious female at 2.36pm and that rapid response paramedics transported the woman from Kerr Street to the Causeway Hospital.
A spokeswoman for the RNLI Portrush Raft Race said good weather had drawn huge crowds to the event and praised the emergency services' quick action to help the woman.
"It was very fortunate the emergency services were at the scene," she said. The lady was a member of the public and not participating in the raft race.
"The start of the race was only delayed by about 15 or 20 minutes.
"We wanted to make sure she was OK and she was taken away to hospital as a precaution."
A spokesperson for the Northern Health Trust said last night the woman had been discharged after treatment.
The 32nd RNLI Portrush Raft Race took place on Saturday and Sunday at Portrush Harbour on the Causeway coast to raise funds for the RNLI.
The raft race is a very popular family event that draws big crowds over the bank holiday weekend.
Portrush Lifeboat Station has been operating for more than 145 years and the crews have been presented with 28 awards for gallantry.
Today the station operates both an inshore and an all-weather lifeboat.