All 25 occupants of a Hawaii tour boat were rescued after the 30-foot vessel struck rocks while backing into a cave, possibly after currents shifted.
Kanaloa, carrying 23 passengers on a snorkeling expedition, was damaged July 10, 2011, along Maui's Le Perouse Bay. Waves pushed the vessel onto rocks while it entered the cave, the U.S. Coast Guard said.
The Coast Guard is probing whether the captain was careless when he entered the cave while swells were kicking up along Maui's southwestern coastline, said Lt. Frank Bullock, a Coast Guard investigator. The operator has since prohibited its tour boats from entering caves.
Home ported in nearby Kihei, Kanaloa frequently entered that cave and the crew of two are very familiar with the waters. The weather was clear and sea conditions were not out of the ordinary. Bullock wasn't sure of the wave heights, but he said there was no high-surf advisory for the area.
"The sea state and the swell may have been a contributing factor, but it was more due to the captain's judgment," Bullock said.
Kanaloa is a rigid-hull inflatable boat powered by twin 225-hp outboard engines. The accident happened at 0826.
One of the engines was damaged and an EPIRB was activated. The Coast Guard made radio contact and sent a 45-foot response vessel.
Kanaloa is operated by Kihei-based Blue Water Rafting. Owner Mark Derensis confirmed that weather and sea state do not fully explain the accident.
"A receding south swell, however, would be considered a factor in producing the waves causing the Kanaloa to make contact with the walls of the cave," Derensis said.
The tour boat was able to navigate back out of the cave on its own. It had damage to both sides after being bounced around on rocks. Bullock said the cave is 30 to 40 feet wide and 50 to 60 feet long.
"What caused the damage was the back-splash off the back of the cave," Bullock said. "The initial impact and the initial damage occurred on the starboard side bow with the rocks, and because of the back-splash to the other side, the port quarter was damaged."
The coastline near Kihei is popular for touring and snorkeling because it's the site of Maui's most recent volcanic activity, the lava from which created unique sea grottos and arches. Weather conditions, however, are known to be very changeable, and sudden swells in the summer can create hazardous conditions for snorkeling, diving and boating.
Blue Water Rafting's boats typically did not stay long in the cave.
"The company had a practice of not hanging out in there," Bullock said. "There was no snorkeling going on in there. They would go into the cave and maybe stay up to a minute or two minutes, tops, and they would get out of there. It's just to be able to show the cave and the rock formations."
The Coast Guard boat evacuated 18 occupants. Kanaloa's sister vessel, Pineapple Express, picked up five and a good Samaritan fishing boat removed two. Pineapple Express escorted the damaged tour boat back to its berth at Kihei.
Derensis said his vessel had punctures and tears in the bow and starboard side and damage to the bow deck area and canopy at the stern. He said the hull never hit bottom.
"Steering was disabled but sustained minimal damage, and the twin outboards suffered damage to the cowlings and a broken spark plug on one motor," Derensis said. Kanaloa was fully repaired and back in service by August.
Entering a cave requires keen attention to currents and waves, the Coast Guard investigator said.
"The biggest danger would be anytime that you choose to restrict your maneuverability, you have to be extra vigilant to be on the lookout for a change in the weather or the sea state," Bullock said.
He said Blue Water Rafting agreed to drop the cave tours as part of its snorkeling trips.
