Deane Gonzalez never envisioned having to spend part of his Easter Sunday swimming for his life.

But that's what he did after someone cut his boat's anchor line while he and a dive buddy were some 60 feet down in Maunalua Bay about a mile and a half off 'Aina Haina. They were shooting video of rare cowrie shells.

"We heard a motor revving, and I looked up to see another boat nose to nose with my boat," Gonzalez said last week, surveying the ocean off Hawai'i Kai. "The next thing I see is my boat drifting rapidly toward Diamond Head."

Gonzalez said he made a "split-second" decision to perform an emergency ascent. He exhaled as hard as he could on the way to the surface and then swam after his boat as fast as his 65-year-old body would allow.

His 30-year-old, 21-foot Boston Whaler Outrage was drifting about 300 yards away from where he surfaced. But with the aid of his electric dive scooter, his dive fins, his Navy training, his years as a city and county lifeguard and more than 40 years experience diving in Maunalua Bay, Gonzalez managed to catch up to the boat after an all-out 8- to 10-minute swim.

Fortunately, the key to the boat's twin Johnson outboards was still in the ignition, right where he had left it. After five to 10 minutes of "dead reckoning" back in the direction of where he had surfaced, Gonzalez spotted dive partner Michelle Liporto, a registered nurse, waving her hands over her head, and plucked her from the water.

It was on the way back to shore that the two spotted signs that something ominous, if not criminal, had happened.

"Someone had cut my three-quarter-inch braided nylon anchor line," Gonzalez said. "I always over-rig in the interest of safety. That line is strong enough to tow the Queen Mary."

Now, all that was left of the anchor line was a two-foot section hanging from the cleat on the bow of Gonzalez's boat. The rope was already starting to unravel, but each strand was the same length, meaning the line had been cut.

Then Liporto found the short, front deck of the boat littered with small chunks of shattered safety glass.

Since his boat has no windshield or other glass, Gonzalez concluded it must have come from the other boat.

He has his own theory of what happened, admittedly based solely on conjecture.

"I think someone was out there zipping around on their daddy's boat, high on drugs or drunk, drove into my boat and panicked. I think they thought if there was no crime scene to investigate, there was no crime, so they cut my boat adrift and drove off."

In doing so, the culprit disregarded the regulation "diver down" flag that Gonzalez had fastened to the boat's antenna.

In his mind, leaving two divers to fend for themselves a mile and a half from shore, in choppy seas with the winds blowing out of the northeast at 20 to 25 knots was tantamount to attempted murder.

Attorney Roy Bell, who represents Gonzalez, is not so sure the incident rises to the level of attempted murder unless it can be shown that someone was deliberately trying to harm or kill Gonzalez and Liporto.

"But I can understand where Deane's coming from," Bell said. "When somebody does something that leaves two people stranded a mile and a half from shore — that leaves them in the middle of the ocean with no way to get back — that's a very serious matter," Bell said.

An argument might be made that what happened to Gonzalez and Liporto amounts to recklessly endangering the health and safety of others, Bell said.

Gonzalez and Liporto called police when they returned to the Maunalua Bay boat ramp in Hawai'i Kai.

Police arrived, looked at the boat and immediately turned the case over to the state Department of Land and Natural Resources.

A police spokeswoman said the DLNR has jurisdiction over events that occur on the ocean side of the vegetation line along the shoreline.

A DLNR officer arrived about 30 minutes later and took statements from Liporto and Gonzalez.

Since then, Gonzalez and Bell have faxed, written letters to and telephoned the DLNR to check on the status of the investigation. More than three months later, neither has gotten a response.

DLNR spokeswoman Deborah Ward confirmed that the department's Division of Conservation and Resource Enforcement received a complaint from Gonzalez and opened an investigation, which she said is ongoing.

Ward said agency officials are checking to see why no one in the department has responded to the phone calls and letters from Gonzalez and Bell.

Gonzalez hopes the investigation can determine who cut the anchor line.

"Somebody out there must know something," Gonzalez said. "I just want to know why someone would do something like that."