SEASIDE visitors have been warned to be careful at Felixstowe's beaches after two children were nearly swept away by a massive wave.John Alderton, from Ipswich, had been enjoying a day at the beach when a large vessel created a six-foot wave which could have engulfed his grandchildren.

SEASIDE visitors have been warned to be careful at Felixstowe's beaches after two children were nearly swept away by a massive wave.

John Alderton, from Ipswich, had been enjoying a day at the beach when a large vessel created a six-foot wave which could have engulfed his grandchildren.

The retired civil servant said that if his granddaughters had been playing by the shore they might have been swept away by the massive wave and could have drowned.

This is one of fewer problems concerning freak waves caused by vessels since the Sea Cat ferry was forced to slow down three years ago after it was blamed for creating a number of dangerously high waves.

"This was on Monday and we were on the beach with our grandchildren between the pier and the amusement park," recalled Mr Alderton, of Bullen Close, Bramford, Ipswich.

"It was almost low water and a large blue container ship which comes in daily to the port created this wash. It came up the beach half way and luckily my grandchildren weren't there at the time.

"If there had been a youngster on the edge of the water they would have been washed away. It would also have been dangerous if they had been swimming."

His granddaughters Rebecca, nine, and Hannah, seven, were further up the beach with Mr Alderton and his wife, Stella.

They had been drinking tea as they watched the boat go past in the distance but leapt up when they saw the five to six foot wave come crashing towards them.

"It was in its normal approach channel it appeared to be going at a fair old rate.

"We were lucky really if they had been in the water then it would have flung them all over the place," he said of the two young girls.

The wave had swept 25 feet up the beach but it seems few people were effected by it because the resort had not been busy because a dull weather forecast had deterred visitors.

Mr Alderton said he wanted to make people aware about the freak wave so that others would not have to endure the frightening experience.

A spokesman for the council said: "Suffolk Coastal received an anonymous complaint on Monday afternoon that there had been three pulse waves between 1pm and 2pm which came high onto the beach and which appeared to have been caused by a large blue container ship.

"The council passed on this information to the Harwich Haven Port Authority which said it would investigate and issue a warning letter if appropriate. "Clearly we are concerned about this incident and would ask anyone who witnesses anything similar in the future to contact the Port Authority immediately."

Harwich Haven Authority said that the harbourmaster had been informed and that there would be an investigation.