They advised the driver to get his reportedly elderly passengers off before it was pulled out into the surf, and/or rolled, in which case they might have been in danger of drowning.
Sand Safaris owner Sara Kennedy (who could not be contacted yesterday) said in response to comments on the Houhora police Facebook page that the bus was being salvaged on Tuesday night, without damage to the environment.
Senior Constable Knowler did not expect any damage provided the vehicle was removed reasonably quickly. There was no sign of oil or diesel leaking while she was there.
"It is no different to all the other vehicles that use the beach daily," she said.
"If it becomes an issue then I'm sure the council has charges it can bring."
Ms Kennedy said the driver was a local man with more than 20 years' experience, who had fallen victim to a high tide and a "disappearing bluff area with a hole. It's a dangerous beach".
"We are truly gutted but everyone is safe and sound, so that's all that counts," she said.
"My husband and I were devastated as it's his baby."
She also offered "a big thank you" to Senior Constable Knowler, while another contributor to the page said the hole had deepened lately.