HONOLULU (AP) — A yacht-sized passenger boat ran aground in the high surf off a Hawaii beach over the weekend, with the vessel precariously riding a set of powerful waves and appearing to nearly flip on its side before coming to rest.

KHON-TV reported that the events occurred around 8 a.m. Saturday when the swells were peaking and the tide was bottoming out.

Two crew members were on the 60-foot (18 meter) vessel, named Discovery, when it ran aground near Honolulu’s Kewalo Basin Harbor, the U.S. Coast Guard said in a statement.

The reason Discovery had such trouble remains under investigation, and there were no apparent mechanical failures prior to the event, the Coast Guard said. The vessel’s operator reported that he took two large waves to the stern, disrupting his course. The boat lost propulsion after it went aground.

The boat’s fuel, oil and batteries were removed, preventing the threat of pollution, the Coast Guard said. A company planned to tow the boat away at high tide Sunday afternoon.

The grounding was captured on video from various vantage points as onlookers screamed and the Discovery careened down a swell on its side before temporarily righting itself in the surf.

Ramon Brockington, 41, a surfing filmmaker, said he and others had been expecting the higher swells for three days after monitoring weather apps that use data from ocean buoys. He was filming body surfers in an area off the harbor known as Panic Point when the passenger boat barreled into his line of sight, riding a wave.

“Basically they were coming in trying to beat this wave,” Brockington told The Associated Press. “And the boat didn’t have enough power to get in front of this wave. So what happened was a wave ended up picking up the boat, and the captain basically lost all steering whatsoever.”

The powerful surf pushed the vessel into water that’s about two-feet deep or less, Brockington said. He’d never seen anything like it.

“Basically, the boat was surfing like a giant surfboard,” he said. “I’ve never seen a boat of that size and caliber being picked up like a toy and basically launched across the beach.”

The Discovery eventually drifted against a concrete wall that lines the shore.

Atlantis Adventures, which owns the Discovery, said in a statement that the two experienced crew members aboard were not injured.

“We are working closely with all government regulatory agencies to have the shuttle boat safely removed from where it was grounded, towed back to its pier location and thoroughly inspected before it is returned to service,” Atlantis Adventures said.

The boat is Coast Guard certified and regularly undergoes Coast Guard inspections, the company said. Its captains ferry people to and from the Waikiki submarine dive site and are trained and Coast Guard certified.