According to the police summary of facts, he told his passengers that getting down the beach "might be touch and go."
Upon reaching the Bluff it became apparent the tide was 'significantly high," with rough surf around an outcrop of rocks that had to be passed on the seaward side.
Robson parked for some time, as did the drivers of two bigger buses, to wait for the water to recede. The bigger buses subsequently drove through the surf successfully, and Robson proceeded to follow, but pulled away and waited again, trying to judge the wave pattern.
He tried again a short time later, but water flooded the engine and the bus stalled. Robson was unable to start it again, waves hitting the vehicle, which lost traction, until it was floating and pointing out to sea. As the waves hit the bus it lurched on to its side before righting itself.
Robson allegedly told his passengers "This isn't good," and told them to get off the bus. They helped each other through the surf to the safety of the rocks, with one passenger tearing a leg muscle when she fell into the water.
Robson told police the incident had occurred several hours after high tide, and that it should have been safe to drive around the rocks.
Robson, however, told the court there was nothing unusual about the conditions. His practice was to wait and watch, and time his run past the rocks. He had driven through water 30cm deep many times, as had many other drivers. It was a normal thing to do.
This time, however, as he began to "crawl" around the rocks, slightly closer to them than the buses that had preceded him, his front left wheel dropped into a hole. The bus stalled and would not re-start. At that stage, the water was no more than 30cm deep, but a sweep from further along the beach surged towards the vehicle and hit it.
Robson knew he would need a tow to get the bus out of the hole, but another bus driver declined to help given the risk it would represent to his vehicle.
Robson said he had been embarrassed, and was sorry to hear one of his passengers had hurt her leg, but he thought carefully before trying to get around the rocks, and, given his experience, had not expected any problem.
He also told the court that water did not got into the engine.
Another tour bus driver, Matt Barnett, told the court the incident had simply been bad luck.
Robson had followed normal procedure and if his wheel had not hit the hole there would not have been a problem.
