A close encounter with a big shark added an edge of excitement to this summer's first beach weekend when bathers were sent scurrying from the surf on three occasions at Papamoa Beach yesterday.

The 2.4m thresher shark swam so close to shore chasing fish that at one stage it was clearly visible as it sliced through the shallows.

Papamoa Surf Life Saving Club's acting patrol captain Ross Merrett said the shark was seen swimming around the back of the flagged area at 1pm and when it did not move away, swimmers were told through loud speakers to leave the water.

Swimming conditions were not exactly pleasant with large numbers of jellyfish floating about. When 10-year-old Morgan Lyall heard the alert he thought it was because of a big poisonous jellyfish.

"If we knew it was a shark, we probably would have sprinted out."

The appearance of the non-aggressive shark coincided with the hottest part of the day and the beach was packed with people.

Guards waded into the shallows to underline the warning. Senior guard Ashleigh Cleverley said when bathers who asked were told what the trouble was, their walk turned into a rush.

An inflatable rescue boat was used to scare fish off to encourage the thresher away.

The beach reopened 10 minutes later once the shark had swum off.

Half an hour later it was back, coming right into the shallows to chase fish and herd them into edible quantities by swimming in circles and using its tail to thrash the water. When it returned a third time 30 minutes later, Ashleigh said some swimmers started to dawdle and even sit around rather than get out.

Mr Merrett said people became curious and some bathers waded back into the surf to waist depth get a closer look.

Guards told them to back off because a blow from a thresher's tail was extremely dangerous and sometimes fatal.

Mr Merrett said it was not uncommon to see thresher sharks in the area in front of the clubhouse, with half a dozen sightings during the patrol season.

At least two sharks were feeding in the shallows along Tauranga's coastline yesterday because the second warning at Papamoa Beach coincided with bathers at Harrison's Cut sighting another thresher.

Morgan and his brother Damon and friend Ayson Collins took it all in their stride.

Ayson said they were not really worried by the drama.

"We were having a fun time - we forgot all about it."

- BAY OF PLENTY TIMES