On a rainy morning in July 2009, Ed Merck was having breakfast on his boat in Lake Tashmoo. He had just completed a 12-and-a-half day sail up the east coast from Florida. Now, moored in a quiet corner of the pond, he was struck by loneliness. “This was supposed to be my dream, my pot of gold at the end of the rainbow, yet instead of holding treasure, I sit in the cockpit feeling the grayness of being alone,” he wrote in his new book Sailing the Mystery. “I even wonder if this adventure has been a colossal mistake.”

The adventure began in May when Mr. Merck sold his home in Foster, R.I., and headed to Florida where he would ready his sailboat Kairos for a trip up the east coast. But his personal adventure began a year earlier, when at age 62 Mr. Merck found himself at a life-changing crossroads.

“I sold my software business and my son went off to college and the marriage I had been in for 17 years dissolved,” recalled Mr. Merck in an interview at his home in West Tisbury. “So my identity, which had been very grounded in my work and my domestic life as a husband and a father, all of a sudden went poof and I didn’t know who I was and it was kind of scary.”

Needless to say it was a difficult time for Mr. Merck. While he struggled with the “what next” of it all, there was one thing he knew for sure -- this was an opportunity for a kind of inner exploration that he hadn’t found time for during his busy life.

“Besides the transition in terms of stages of life, there was also a personal transformation that was lurking,” he said. “What I call ‘the final third’ is more about going inward. I felt very drawn to that, and it got more and more intense the older I got.”

For Mr. Merck, the much more common path of dealing with the final third of life was not an option.

“I wasn’t enamored with this culture’s sort of stock responses to that. Work hard, save a lot of money, and then when you retire you buy the condo in the gated community in Florida, you learn to play golf and you wait ‘til your number gets called,” he said. “That didn’t excite me at all, even though it felt safe. I knew I needed to do something that was really risky, and for me the core of riskiness was leaving behind a big piece of my life.”

So he went all in. He sold his house in Rhode Island and bought a boat, serendipitously named Kairos (which means a propitious moment for decision or action) with the intention of sailing up the east coast. A lifelong sailor, Mr. Merck had never captained a blue water trip like this one but was determined to make the journey. His friends thought it was crazy. His spiritual mentors supported the decision.

He hired another captain, Brett, to accompany him on the trip, and was also joined by his son, Evan, who had sailing experience. They intentionally made no plan, just simply to head north.

The three men set sail in July 2009 and headed up the east coast. There were the usual challenges — bad weather, physical exertion, battles of ego — but for Mr. Merck it was the internal challenge that arose after the trip had finished that outweighed them all.

“The most challenging was sitting in Tashmoo saying ‘okay, so you distracted yourself for a few months but now you are back alone again. What are you going to do now?’” he said.

Mr. Merck would make a few more sailing trips after leaving the Vineyard that fall. Then during a chance encounter after a meditation class back in Florida, he met a woman who asked if he was writing about his experiences.

“That was the day I started writing the book,” he said.

The book, which was published in October, is called Sailing the Mystery and chronicles Mr. Merck’s journey of personal transformation. Last month, on his porch at his new home in West Tisbury, he reflected on the past couple of years.

“I’m living a life with a whole new me. My purpose in life has been totally redefined. For me the purpose is how deep can I drop into the moment, into life and just be comfortable being in this moment? Some days I can do that all the time, but other days I feel like ‘so what are you going to accomplish today, Ed?”’ he said.

Today Mr. Merck enjoys yoga, meditation, writing and playing music with the band River Heart. He has found that the Island offers an environment where he can continue to grow and explore his final third.

“Unsurpassed beauty, diversity in natural landscape, sense of community, feminine energy of landscape,” he said of his choice of settling on the Island.

Four years after he sat at the empty table in his Rhode Island home wondering how to navigate the changes in his life, Mr. Merck is grateful for the risk that he took.

“I sailed into the mystery, only to discover that life is not about resolution,” he wrote. “We just keep adding capacity to engage more of the mystery. And that is the miracle.”

Ed Merck reads from his new book and answers questions on Tuesday, Nov. 12, at the Vineyard Haven Public Library. The talk begins at 7 p.m.