Glenn Miller spent 21 years in the Coast Guard in the Northern New England sector, where the chill North Atlantic provides both rich fisheries and treacherous seas. For nine of those years, he had shipboard duty and served on a Search and Rescue team. Hundreds of times, he said, he went out to look for survivors. Many times, he came back without them.

So it was a hard twist of fate when last January, the now–retired Miller picked up the phone to hear the Coast Guard tell him that his 21–year–old son's fishing vessel, the Lady Luck, had capsized and that his body had not been found. "It brought back a lot of memories when I got the call," Miller said quietly. "Because I used to be on the other end making them."

In the days after the sinking of the Lady Luck, no one could say for sure what had happened. And, after a year of investigation, the Coast Guard in the official report it released recently is still quick to say that, with no survivors and the Lady Luck laying 530 feet underwater on the ocean floor, no one may ever really know.

But they have a pretty good idea.

While anybody who has seen a Titanic documentary knows that underwater investigation has made great strides in recent years, the increasing ability to collect underwater imagery using high-tech submersibles, coupled with sophisticated computer modeling software that naval architects and engineers use, has extended capabilities to a degree that may surprise many boaters. And these tools are being deployed more regularly than ever before. VideoRayThe deck of Marcus Hannah prior to ROV launch.

"The modeling helps us understand how it may have capsized rapidly and subsequently sunk," said Capt. Jim Rendon, who commands the Coast Guard's Northern New England sector and asked for the safety center's help. "It's a difficult task to recreate an accident. Investigations are usually inconclusive when you don't have survivors, or you can't salvage the ship and spot inspect it stem to stern. The computer modeling is about using our tools to the best of our ability to figure out what may have happened in the hopes of preventing future accidents."

Lt. Daniel Cost is a staff engineer at the Marine Safety Center in Washington DC. The Center was created in the 1980s to bring under one roof all the naval architects and engineers who reviewed new commercial ship designs and plans for alterations. Their job has always been to test the stability of vessels. Over the years, they created software computer models whereby they could download ship plans, then simulate a number of different real–life scenarios–water coming on deck, ice shifting in the hold of a fishing vessel for example–to see if a ship design could withstand different pressures and still stay afloat. If not, the models enabled them to suggest revisions that would.

Then came major disasters. The Exxon Valdez dumped 11 million gallons of crude oil off the coast of Alaska in 1989 after running onto a reef. In 1990, the tankship Jupiter, valued at $9 million, caught fire and exploded and was so wrecked it had to be sold for scrap.

The Coast Guard, Cost said, realized they needed to help figure out what had gone wrong. So in the early 1990s, they created the Salvage Engineering Response Team, or SERT. Cost is one of the five–member team. They are available "24/7," Cost said, not only to help with casualty investigations and disasters like the Lady Luck, but also with real–time calls. When the captain of a tug calls after his vessel has run aground, SERT can help him figure out how much horsepower he needs to pull it off.

The way they do it, Cost said, is by using that same structural stability software.