That is the warning from Seahouses RNLI spokesman Ian Clayton after nine people in three separate vehicles became stranded in the rising tide last Thursday.
Seahouses lifeboat crew was launched at 12.52pm to rescue two adults and two children, aged one and five, from one car and three people and a dog in another.
As the crew was bringing the occupants of the first car to the shore, a third car containing two people was seen ploughing into the water. The lifeboat rescued them as well, and their car is believed to have been washed off the causeway shortly afterwards.
The three people and the dog from the second vehicle decided to remain in the refuge box until the tide dropped as the dog had become distressed and aggressive towards the crew.
Two days earlier, as reported in last week’s Gazette, four holidaymakers had to be rescued by the lifeboat.
Mr Clayton said: “It’s not impossible or improbable that someone will drown up there.
“The county council has gone to a lot of trouble revamping the warning signs to make them as obvious as possible. Words fail me.”
The crossing times are published each week in the Gazette but as Mr Clayton pointed out, the people who are getting caught out are visitors.
He ruled out mechanical barriers closing the causeway when the tide is in because of cost and they would deteriorate in the sea conditions.
Meanwhile, the crew was called out on Saturday afternoon to rescue three people after their yacht capsized off Holy Island.
The people had been picked up by another vessel and landed safely on the island when the crew arrived on the scene.
One person, who was suffering from hypothermia and had a heart condition, was airlifted to Wansbeck General Hospital by an RAF Boulmer helicopter.