Two Melbourne families were left in shock as a father and his seven-year-old daughter were swept into the ocean, during a visit to the popular whale-watching lookout.

The father of the two other children, who were hit against the cliff face, yesterday questioned the beach's hazard signage and suggested blocking access during dangerous conditions.

Passing through Warrnambool on Sunday, the two families stopped at Logan's Beach for lunch after spending four days holidaying in Mount Gambier.

While taking photos on the beach's stair walkway, a wave came up to the tenth step and totally submerged the tourists, dragging one man and his daughter to sea.

Melbourne resident Terence Alvares said his two children, aged 12 and 14, were hit against the cliff face but managed to grasp onto some long sea grass, while the others waded back to shore.

"I was on the tenth step and water hit me around my waist; it was that high," he told The Standard yesterday.

"We weren't anywhere near the water. You wouldn't expect anything like that and if you can't swim you'd be in trouble.

"My friend's daughter lost her glasses and lost her shoes."

Mr Alvares said the children just wanted to have a play and had no intention of going in the water.

While car park signage warns of large surf and overtopping waves, there is no reference to the stairway being hazardous at Logan's Beach.

Mr Alvares said he was amazed there were no signs on the beach and access had not been closed in the dangerous conditions.

"There was a real danger of loss of life," he said.

"I want to make sure someone else doesn't have same situation as us.

"My kids were having nightmares last night."

j.pech@standard.fair fax.com.au