A Gold Coast whale watching operator has been issued with a safety notice after 26 people were knocked down by a wall of water during a Father's Day outing.

Spirit of Gold Coast Whale Watching claimed a freak accident saw passengers on the foredeck boat knocked down by the waves.

However, the Australian Maritime Safety Authority on Tuesday found the vessel had inadequate safety procedures and ordered passengers be banned from the foredeck in rough conditions and while crossing the bar.

The vessel has not been prohibited from operating.

AAP