A frightening water rescue after a child became trapped in a small pocket of air under a capsized boat in Wellington is a good reminder of the importance of lifejackets, police say.

The dramatic rescue happened on Sunday afternoon as members of the public frantically tried to break the seal the upturned boat had formed with the water.

The incident happened about midday on Sunday, after a 4.9m boat travelling along the Eastbourne coastline began taking on water.

Worsening sea conditions had forced the skipper to slow down, which allowed the following waves to spill over the stern of the boat, police said in a statement.

The skipper made the decision to return to Lowry Bay but as he turned the boat around, it capsized.

Four adults were thrown clear of the vessel, but the child was trapped in the cabin space, where there was an air pocket.

The adults managed to push the boat towards the shore, where police met them.

An officer from police’s rigid-hulled inflatable boat (RHIB) Hukatai dived under the vessel and rescued the child while the other occupants and bystanders on the beach were attempting to break the suction of the upturned vessel in the waves.

 “Thankfully no one was seriously injured or worse during this incident,” said Sergeant Richard Kennedy of the Wellington Police Maritime Unit.

The boat was equipped with lifejackets and flares, and the child was wearing a lifejacket and the adults were in wetsuits, which are a suitable alternative if they are full body suits and worn at all times.

“The skipper stated that everything happened so fast,” Kennedy said.

“We’re relieved this had a positive outcome, but it could have been so much worse.

“Treat water safety as your top priority for all water activities and get home safely.”

The incident was a “clear example that lifejackets save lives”, said Maritime NZ’s Scott Bernie.

Maritime NZ recommends watercraft users undertake courses such as those available through Coastguard to help them prepare for being on the water.

Advice is also available at www.saferboating.org.nz

“Skippers should not leave the shore if they are not adequately prepared to go out on the vessel they are in charge of.

“Overconfidence can be one of the biggest risks on the water,” Bernie said.

Kennedy said while many people listened to advice around water safety, the message wasn’t getting through to everybody.

“We are still seeing people out there on the water without lifejackets, or children not being supervised, so there’s nothing or no one there to help if they get into trouble.

“We’re talking about things like keeping an eye on children when they’re on the water, putting a lifejacket on, knowing the marine weather forecast, avoiding alcohol while doing water activities, keeping within your limits and generally treating water safety as a priority.

“Tragedy doesn’t discriminate and if something goes wrong, it could happen before you can react.”