Howard Veisz, a retired corporate litigator from New York, took an interest one day in a boat moored on the Mystic Seaport waterfront, a 1926 wooden lighthouse tender from Denmark, Gerda III.

Veisz, who had begun spending time in Mystic after a long sailing trip through Europe and the Caribbean, had become well acquainted with the Seaport, after volunteering to help commission the whaling ship Charles W. Morgan for its 38th voyage in 2014, as an apprentice in the rigging shop.

Gerda attracted Veisz in part because of her story, told briefly on a placard in front of the moored boat, how she was used to rescue Jews from occupied Denmark during World War II, carrying some 300 people secretly and safely to Sweden, right under the Nazis' noses.

Veisz's father and grandparents escaped Germany before the war, and he believes a great uncle and aunt were among the thousands of Jews rescued from Denmark in 1943, just as the Nazis were planning to round them up to be taken to camps.

Gerda also attracted the volunteer in Veisz, looking like she could use some TLC.

So began a relationship between the Danish workboat and the retired lawyer, who ended up dedicating volunteer time at the Seaport to do maintenance and chores on Gerda.  He also threw himself into learning more about the boat, eventually traveling to Denmark, where he tracked down historical records, found accounts from the rescued and talked to relatives of the original crew.

His resulting book, "Henny and Her Boat: Righteousness and Resistance in Nazi-Occupied Denmark," went on sale this week at the Seaport bookstore.

On Saturday, to mark International Holocaust Remembrance Day, Veisz will give a talk about his book prior to a screening of "Across the Waters" a Danish film about a Jewish musician and his family who made an escape to Sweden like the kind made possible by Gerda and her crew.

The event, sponsored by the Seaport, the Jewish Federation of Eastern Connecticut and the Museum of Jewish Heritage of New York, which owns Gerda but keeps her for display in Mystic, will begin at 2 p.m. at the Mystic Luxury Cinemas.

Veisz's attention to Gerda coincides with plans to give the boat a more prominent role at the Seaport. Indeed, it is a powerful historic monument, one that tells a remarkable war story of conviction and heroism, the brave Danes who risked so much to save their fellow citizens.

A full restoration, beginning with the rebuilding of its original 1926 diesel engine, is scheduled to start this spring. Eventually, the New York museum and the Seaport plan to make the boat seaworthy again, so that it will be able to tour, including, no doubt, a visit to the New York waterfront, near the Museum of Jewish Heritage in lower Manhattan.

Veisz has pledged any money he makes from his book to the project. A signing at the Seaport bookstore is planned for 1 p.m. to 3 p.m. Sunday.

Veisz is especially pleased by the impending work on the engine. The distinctive sound of the big old diesel firing up, he said, must have meant so much to the rescued huddled in the hold, waiting for their trip to Sweden and freedom to finally get underway.

The descriptions of Gerda's rescue voyages in Veisz's book are fascinating. The boat was owned at the time by the Danish government and made daily trips to service buoys and lighthouses.

It was the daughter of the commander of the lighthouse service, a civilian employee of the service, who recruited Gerda's crew of four to help with the rescue effort.

Jews in Denmark went into hiding in 1943, when word of German plans to round them up leaked out. A dragnet planned for one specific night, with troop ships at the ready to carry away the captured, came up largely empty-handed.

Danes were hiding Jews in their homes, in hospitals and in warehouses, with an aim of using the only possible escape route: by water to non-occupied Sweden.

All manner of boats were pressed into service, and many were captured by the Germans.

Gerda turned out to be especially effective and Veisz believes she probably carried more refugees than any other boat — as many as a dozen or more every night for a month.

The lighthouse tender was moored alongside a warehouse, and Henny Sinding, working with the resistance movement, each night rounded up people who would be rescued. She is the Henny of the book's title.

Even while German sentries were walking up and down the wharf where Gerda was moored, Sinding would rush the rescued quickly from the warehouse to the hold of the boat before the guards circled back. The German guards would later, most nights, come on board and greet the crew, sitting sometimes on top of the hatch for the hold, where the rescued waited anxiously below.

Veisz includes the recollection of one of the rescued, who tells of peeking through a crack in the hatch as Gerda, leaving port, passed under bridges with German soldiers marching overhead.

In the end, the Danes saved at least 7,742 Jews, many from families that had been part of Danish society for generations.

After the rescue of Jews, Gerda went on to help others in the resistance movement escape the Nazis. After the war, the tender stayed in the rescue business, this time in the Cold War, helping bring to Denmark those fleeing East Germany by water.

Veisz credits his wife, Lorraine, with being part of a partnership in telling Gerda's story.

The boat also seems to get some credit for bringing the couple permanently to Mystic. They bought a house here over the summer and have put their 50-foot sailboat, on which they primarily lived for a few years, on the market.

Veisz's telling of the Gerda rescues and the conviction of the Danes seems to especially resonate today.

Indeed, as Veisz writes at the end of the preface to the book: "Their story is a compelling reminder of what good people can accomplish when they resolve to combat bigotry and oppression."

This is the opinion of David Collins.

d.collins@theday.com