The Coastguard has issued a warning after three serious incidents at the mouth of Raglan Harbour.
A boat was overturned by a wave on what is known as the Raglan bar on Thursday morning.
It is the third incident on the sand bar in the past two weeks, including the drowning of a fisherman.
Coastguard nothern region duty officer Mark Fletcher says the west coast can be lethal for people who enter the water without learning about the area first.
He says all skippers should make contact with the Coastguard before crossing the sand bar.