It might look easy, but crossing from Taieri Mouth to Moturata Island can be ''extremely hazardous'', authorities warn.
Four teenagers prompted a Search and Rescue (SAR) call to the area on Saturday night.
The three males and one female aged between 11 and 14 walked across the sand bar at low tide from Taieri Mouth to the island, but were caught by a rising tide on return.
They managed to reach Taieri Mouth before police and Brighton Surf Life-saving Club members arrived, having been called by resident and SAR water adviser Keith Simon about 9.30pm.
He said such incidents were becoming more common and people needed to be aware of the dangers when crossing to Moturata Island.
Senior Sergeant Steve Aitken, of Dunedin, reiterated the message and said the teenagers were lucky to avoid a much worse outcome.
SAR incident controller Brian Benn said the group had checked tidal information for Dunedin, but that was not applicable to Taieri Mouth.
''Tide times vary up and down the coast. The group also left it fairly late in the evening to return to Taieri Mouth,'' he said.
Snr Sgt Benn said the area was notorious for SAR calls.
A few times a year people were caught by rising tides as they tried to cross between Taieri Mouth and Moturata Island, and there were even more incidents each year of people getting into trouble while crossing the bar in boats, he said.
''You have to be careful about picking the right time and the right tides. We would prefer to see people back at Taieri Mouth well before dark.''
Snr Sgt Brian said the crossing could be deceptive. People thought it would be easier and faster to cross than it usually was, he said.
''It's pretty hard work. You think it's not too far and it looks fairly easy, but when you start wading in waist-deep water which is moving against you and you've got 1km to go, it's hard.''
