FRYE ISLAND — An October 1986 explosion aboard a Soviet submarine that threatened the East Coast with nuclear devastation was just one chapter in a larger story, says the retired Navy captain who helped bring the incident to light.

Peter Huchthausen says thousands of deaths and untold environmental damage are the legacy of a decades-long string of accidents involving the Soviet navy that have long been shrouded in secrecy.

Huchthausen, an Annapolis graduate whose 28-year career was capped by his assignment as U.S. naval attache in Moscow, chronicled the sinking of the ballistic missile submarine K-219 off Bermuda in his recent book, “Hostile Waters,” (St. Martin’s, $23.95).

The book, co-authored by Igor Kurdin, who previously served as executive officer on the ill-fated submarine, and novelist R. Alan White, was the basis of this summer’s HBO movie starring Rutger Hauer and Martin Sheen.

Sea water leaked into a missile silo on the K-219, mixing with the liquid fuel to cause a gas buildup that triggered an explosion and fire. The crippled sub surfaced, posing a risk that the 15 missiles, targeted at cities such as New York and Washington, might “cook off,” blowing up the boat’s two reactors and spewing radioactive debris into the atmosphere.

“Worst case, according to nuclear reactor people, was if the submarine did not sink and she sat on the surface and smoldered, it would have been worse than Chernobyl,” Huchthausen said, noting that fuel in the reactors was more highly enriched than the fuel in the Ukraine power plant.

On one level, his book is a breathtaking tale of bravery and dedication, exemplified by the 21-year-old seaman who voluntarily entered a live reactor and cranked a crude hand tool to shut it down. He was one of four crewmen killed in the accident; others later died or were made ill from radiation exposure.

“Hostile Waters” also points out the sorry state of the Soviet navy, particularly as it scrambled to keep pace with the U.S. military buildup of the Reagan era during a critical period of the Cold War.

It was during Huchthausen’s stint as naval attache that Soviet society become more open, allowing long-suppressed accounts of military disasters to be aired for the first time.

“I was there at a unique time. The veil of fear disappeared and the Russians sought us out,” he recalled during an interview at his summer home on Sebago Lake. “I had Russians eager to give me information.”

One sensational revelation followed another: a 1955 explosion aboard a battleship at its Black Sea anchorage that claimed more than 600 lives; the 1974 loss of a guided-missile destroyer and the subsequent cover-up; and a blast the same year that destroyed the entire missile storage area of the Soviet Northern Fleet.

Safety conditions were perhaps most egregious in the submarine fleet, where eight vessels were lost in the program’s first decade alone. Fires, radiation accidents and sinkings claimed hundreds of lives.

The environmental record was equally appalling. The Soviet navy dumped nuclear waste into all the world’s oceans on a regular basis, Huchthausen said, with the worst of the damage in the Sea of Japan and the Barents Sea, part of the Arctic Ocean between Norway and Russia.

That sordid history is the basis for his upcoming book, tentatively titled “Of Sunken Subs and Samovars: Revealing the Hidden History of the Soviet Navy,” which Huchthausen had placed on the back burner while completing “Hostile Waters.” He has since completed research on the new book and hopes to see it published later this year.

In gathering material for the book about the K-219 and its cat-and-mouse encounter with the attack submarine USS Augusta just prior to the explosion, Huchthausen was dependent largely upon Soviet sources. U.S. submariners, bound by a “blood oath” of secrecy, kept mum about the incident.

The Russians had taken a similar oath, Hutchausen said, “but theirs died with the Soviet Union. And as the wall of secrecy began to fall under Gorbachev, they began to talk.”

“Hostile Waters” sheds light on one of the most intense battlegrounds of the Cold War — the undersea world in which U.S. and Soviet submarines operated cheek to jowl on a daily basis, engaging in a dangerous game in which collisions were not unknown.

It was a tableau in which audacious commanders stopped just short of firing weapons.

By some accounts — the film adaptation of “Hostile Waters,” for example — the explosion aboard the Yankee-class Soviet “boomer” followed a collision with the Augusta. But Huchthausen says the worsening leak was more likely caused when the Soviet skipper executed a radical evasive manuever known to U.S. submarine crews as a “Crazy Ivan.”

The undersea face-off between the two superpowers was unequal. U.S. technology was far superior, enabling U.S. submarines to operate silently and keep tabs on their often obsolete Soviet counterparts while escaping detection themselves.

In one area — intelligence — the Soviet Union clearly prevailed, Huchthausen said. Communications codes and other information gleaned as a result of the notorious Walker spy case and other compromises proved invaluable to the Soviet navy and, in the case of the K-219, alerted its crew to the presence of the Augusta.

“It was bad, very bad, much worse than we like to admit,” Huchthausen said. “They were reading our mail.”

Despite the breakup of the Soviet Union and the new relationship between Russia and the United States, the undersea cat-and-mouse games still go on, says Huchthausen, who is aware of three collisions since the end of the Cold War.

“They are still building submarines, but at a much slower pace,” he said. “They are keeping their submarine-building capability and the submarine-design capability alive, although it’s been reduced to a tiny fraction of what it had been.”

Excerpts from “Hostile Waters” by Peter Huchthausen, Igor Kurdin and R. Alan White:

The chemical explosion inside silo six ejected the smashed remains of the RSM-25 rocket and its two warheads into the sea. Some of the high explosive surrounding the warheads’ plutonium cores also detonated, scattering radioactive debris both into the ocean and down the shattered silo. The blast caused the silo’s thick steel skin to split like an overripe banana. A cataract of seawater, plutonium fragments, and spilled missile fuel roared through the fissure. Its thunder drowned the screams of men and the groans of the hull as K-219 plunged out of control. The bottom of the Hatteras Abyss lay three and a half miles below her keel.

A blast-furnace gust flowed out so strongly he could feel it through the insulated suit. Better not to waste time. He folded himself through the small hatch, then stood up inside the reactor space.

The two reactor vessels were before him, two domed cylinders seething with nuclear fire. The heat was intense. There was an odd, ozonelike smell to the air.

A sinking submarine stuffed with nucear poisons. They should all be paddling away from K-219 as fast as they could swim. Who cared if a reactor blew up right next to America? It wasn’t as though they were bobbing off Odessa. What Russian would pay a kopeck to keep enriched uranium from dusting American beaches?

Belikov was paying a good deal more than a kopeck. He knew he was taking a huge dose of radiation by standing here. Enough to sterilize him for sure. To keep America safe. That was what he was sacrificing his manhood for.

It was really a crazy world.