An eyewitness has described what looked like a sea rescue amid huge swells that hit the Bay of Plenty in the weekend.

Surf lifesavers were conducting Inflatable Rescue Boat training at Omanu Beach on Sunday afternoon, when one participant appeared to have been knocked from the boat and a rescue was mounted.

SunLive has seen footage of the incident, filmed from the Omanu Beach car park, which appears to show events as they transpired at about 1pm Sunday.

In what appears to be a simulated rescue, two figures are seen on the IRB battling through the choppy waters, which at the time were registering at up to 14 foot high.

A strong wave makes contact with the IRB, almost tipping it, and, seemingly, washing one of the passengers overboard.

The remaining crew member is then seen flagging to the shore for assistance.

In the video, one person can be heard to say 'she fell out” in relation to one of the people in the water.

One eyewitness says he wandered down to the beach whilst waiting for his fish and chips order, when he noticed something was going on.

'The sea was wild,” he says.

'At first it seemed to just be part of a training exercise, but things seemed to escalate really fast.

'They sent out another rescue boat and pulled a couple of people from the white water. They were all wearing helmets and vests and stuff but one seemed to be in a bad way.

'The water was coming in fast as and right up to the dunes so it was fairly gnarly out there.”

Whilst he could not be 100 per cent sure it was not a completely simulated incident, he suggests the physical condition of one of those involved indicates this was a real life event.

'One of the young girls that got into trouble seemed to be struggling real bad after,” he says.

'She had to lean on two other guys to get back up the beach.”

But the eyewitness also praises the 'rapid” response of the surf lifesaver team in what were extremely challenging weather conditions.

'At the end of it all everyone was super calm,” he says.

'The lifeguards did an incredible job, it was all over in a couple of minutes but yeah it could have been a lot worse.”

Omanu Beach, as was the case with much of Mount Maunganui, was battered by a huge swell caused by a low-pressure system northeast of New Zealand over the weekend.

The base track of Mauao and Moturiki/Leisure Island were closed due to safety concerns related to the swell.

Surf Life Saving New Zealand lifesaving manager for Eastern Region Chaz Gibbons-Campbell confirms that an IRB training exercise was underway at Omanu on Sunday, but was unaware of any incident in particular.

However, he spoke of the busy day SLNZ had across the region.

'It was a pretty busy day on Sunday,” Chaz says.

'The Omanu guys, just at the start of their training, also responded to some surfers in trouble down closer to Rabbit Island but by the time they got down there they were all back in safely.

'After that they were back to their training which is when, probably, this incident occurred.”

Chaz also expressed his relief and appreciation that lifeguards appeared to have performed their duties in a calm and efficient manner.

'Obviously the winter time is the right time for the training to happen,” he says.

'Getting these guys skilled up for the summer is really important.

'It sounds like, obviously, these guys followed all their training protocols and had safety in place to support their team.”

SLNZ will update SunLive if any more information related to this incident becomes available.

Omanu Beach Surf Life Saving Club have so far been unable to respond to comment from SunLive.

The bystander who shared the video of the incident on social media has also been approached for comment but was not willing to discuss it further until the surf club had returned comment.