Dan Boyle's heart, as compassionate as his temperament could be combative, gave out for the second and final time last week. He was exercising, as he did daily and religiously, at the Westerly YMCA.

Seven years earlier, the first time his heart failed him, he'd been swimming in one of the Y's pools and was rescued and resuscitated by young lifeguards, transported to Yale where he underwent bypass surgery and lived to swim his mile or more each day until his heart quit for good. He was 76.

Dan was my friend and neighbor for nearly 40 years. From time to time, he was also my vexation, as I, a decade younger, was no doubt his. Thus, we negotiated the rougher edges of age, opinions and male bonding. We got along. Unfailingly, he was my patient and thoughtful tutor. He was my rabbi, was Daniel Patrick Boyle Jr.

During my three decades writing for The Day, I subjected Dan to more exposure in print than he probably appreciated. I wrote about him when he was a feisty union leader and teacher of the deaf at the former Mystic Oral School, from which he was fired twice and each time won reinstatement.

I wrote about him when he ran, as a Democrat, for the 43rd District House seat, only to have his opponent, David Johnstone, die weeks before the election. He then found himself confronting Frank Turek, longtime congenial director of the Stonington Community Center, who'd been nominated to replace Johnstone. As Dan liked to say, with no little resignation, he ended up running against Jesus Christ. He lost.

I wrote about Dan when he was trolling the waters in winter as an independent lobster man; when he tried to foist, with some winking guile, one of his beagle's ceaselessly howling puppies on us; when we ventured a few times to a venerable Russian steam bath in rural Wallingford; when we let ourselves be cajoled into an Iron John-era men's group that met in Stonington Borough, mercifully not for long; and when we traveled to Ireland together in February 1991.

We visited relatives of his on their humble farm in Castlebar, toured around Galway and Dublin, stopped by chance in Cahir, the birthplace, we learned, of one of Connecticut's most popular governors, the late John N. Dempsey, and managed to raise a glass or three in what seemed like every pub in the West of Ireland.

It was in Ireland, in Clifden, in Connemara, that he bought me a tweed cap to commemorate the trip, one I continue to wear for comfort and now in memory of an abiding friendship.

He was a justice of the peace in Stonington, harbormaster in Stonington harbor, dock master for the contentious Stonington fishing fleet. He kept bees and then raised turkeys at his home across the road from us.

As a younger man, he spent summers as a park ranger in Acadia National Park in Maine and, in his mid-70s, he was a lifeguard at Greens Harbor Beach in New London. In his 60s, always robustly fit, he made the four-day trek to the heights of Machu Picchu.

He fiddled with the banjo and he was a familiar presence at the Portuguese Holy Ghost Club in the borough. More recently, you were just as likely to find him at libraries in Stonington and Westerly, and at the independent film series at the Groton Public Library. He was fastidious about his appearance and health. Beset with blood sugar ills later in life, he brought the levels under control by diet and discipline.

Raised in working class Pittsfield, Mass., he matriculated from high school to the Marines and eventually to a master's degree in educating the deaf. Married twice, he fathered five children. He was loyal.

He could rage at a whim. Mostly, he was determined to challenge himself, and, in particular, his mind. He read, he studied, and he pursued whatever intrigued him, physical and intellectual. When he died, he had a recording about Napoleon in his car.

He was a tough, stubborn resourceful man with a fierce intelligence and a volatile soul, and one of those precious finds in life, a friend.

Steven Slosberg, a former columnist for The Day, retired in 2007. He lives in Stonington.