An 819-foot Bahamian oil tanker was apparently hit amidships Wednesday night by a 108-foot Rockland fishing trawler after it attempted to hail the smaller vessel, a U.S. Coast Guard investigator said Friday.

That call went “unanswered,” Lt. Daniel McLean of the Marine Safety Detachment in Belfast said.

The collision between the fishing vessel Sunlight, owned by O’Hara Corp. of Rockland and the Erik Spirit of Nassau, Bahamas, occurred in international waters about 20 nautical miles southeast of Portland Head Light near the end of the northern outbound shipping lane. The accident was reported to Coast Guard Sector Northern New England around 11 p.m.

Before the collision, the Erik Spirit had been moored in Portland off-loading crude oil.

According to a Web site, TeeKay Shipping Ltd. of Glasgow is manager for Erik Spirit LLC, whose port is Nassau, Bahamas. The oil tanker was built in 2005 by Samsung Heavy Industries Co. Ltd., Koje Shipyard in South Korea.

At the time, visibility was two to three miles in rain with 4- to 5-foot seas and southwest winds 20 to 25 mph, McLean said.

According to McLean, witnesses on the fishing vessel said the trawler collided with the tanker amidships on its port side.

Asked if the tanker were damaged, McLean said, “It was dark,” so witnesses could not tell.

The helmsman, who is not being identified, was the only person injured in the collision. He suffered a gash on his forehead that required 14 stitches, McLean said.

The fishing vessel captain, whose name also is being withheld, was sleeping at the time of the collision and was “thrown from his bed upon impact,” McLean said, noting the captain had been relieved from the helm at 9:30 p.m.

The Sunlight had four people on board, and it is unknown how many crew were on the tanker. McLean noted that tankers of that size typically have a 20-person crew.

Frank O’Hara Jr., owner of O’Hara Corp., could not be reached Friday for comment.

Information derived from the investigation indicates the Erik Spirit hailed the Sunlight on a VHF radio before the collision, McLean said. However, the fishing vessel crew did not hear any radio call nor did they attempt to radio the tanker. According to the Sunlight crew, neither vessel used whistles, McLean said.

Before the ships made contact, the captain was sleeping and two crew members were watching television in the galley. The helmsman was at the helm.

“I have no doubt of his alert level,” McLean said of the helmsman. “Fatigue was not a factor.”

When the bow of the Sunlight struck the tanker amidships, all lights went out on the fishing vessel.

The fishing crew immediately put their training into action, McLean said, grabbing their survival suits “thinking the worst.”

“They were ready to take extreme action, which was good,” he said, but power was restored and the watertight bulkhead on the bow worked.

During McLean’s inspection of the Sunlight in Rockland on Thursday, he found that an escape door on the powerhouse or bridge was sprung by the collision, which could have trapped crew.

The crew indicated they had a significant amount of training, McLean said, but it “still didn’t prepare them for the sheer shock of it all.”

The collision caused rips in the 3/8-inch to 1/2-inch steel bow.

“Obviously, that hull was compromised in that area,” McLean said, but the watertight bulkhead kept salt water from coming into the boat. That compartment is used for fresh water, which was lost in the collision.

The threshold for an investigation of a commercial vessel accident is $100,000 damage, McLean said, noting the Sunlight owner told him the damage far exceeded that. The tanker owner has offered to fill out a Coast Guard report, which is not compulsory in international waters, McLean said.

International Rules of the Road for navigation “makes clear there’s always joint responsibility to stay out of each other’s way,” McLean said. The rules say that there is a “give way vessel” and a “stand on vessel.”

“Early indications point to the fishing vessel being the give way vessel,” he said.