Time is of the essence — an age-old adage.

Nobody had to tell Rubin Cronig. At just 24 years of age, he has been embodying the mantra since he was 10.

Mr. Cronig was an elementary school entrepreneur, selling his hand-made jewelry with his mother’s knit clothing at the Artisans Festival. He learned goldsmithing from Paul D’Olimpia as a middle schooler. At 16, while a sophomore at Martha’s Vineyard Public Charter School, he started his first official business: Rubin Douglas Timepieces. Appropriate for someone who wastes no time, it was a watch company.

“I liked watches,” he said, “so why not?”

An experienced watchmaker may have had a few reasons for the spunky schoolkid. The high-end watch industry is an exclusive one, and it isn’t friendly to newcomers. Watches are also extremely complicated machines, made more difficult to decipher by their small size. Faces, cases, gears, hands, bands — most watchmakers home in on one specialty. Mr. Cronig says that the “true watch guys” are hard to find.

Mr. Cronig didn’t know then that one day he would own not one but two successful watch companies, complete with entirely unique design materials and, of course, a crew of real watch guys.

He started with a phone call. He asked Daniel Waters, well-known artist and poet of Indian Hill Press, to design him a dial. “[Mr. Waters] gave me the response of a true mentor,” recalled Mr. Cronig. “I’ll help you design one.”

The two began meeting several times a week for hours at a time. Rubin learned about computer design and adjusting dimensions. Together, they learned the language of watch making, but they were just dipping their feet. Mr. Cronig’s vision was quite the project, and its architect was still a teenager.

“I was naïve enough to think I could do it,” Rubin said. “I think it was that naivety that kept me going.” And a little help from more mentors.

Introductions started piling up, and it wasn’t long before Rubin awaited a meeting with an intimidating and elusive figure — a German watchmaker who goes by the name Moritz. On the phone Mr. Moritz had made it clear that Mr. Cronig should prepare to pack up his dream and ship it back to the recesses of his mind. This business is tough. When the two met face-to-face, the watchmaker studied one of Rubin’s prototypes. Mr. Moritz stared at the watch with no expression. He looked up at Rubin, still expressionless. Then back down. A smile cracked the man’s stern face. “I’ll help you,” he said.

Mr. Cronig began assembling his team and selling products.

Next on the agenda for the young entrepreneur was college. Rubin attended Wheaton College in Norton. Almost every week, he’d spend a morning and afternoon in class until around 5 p.m., and then head down to New York city for meetings with retailers who sold his watches. He’d stay overnight in the city, attend a second round of meetings in the morning, and get back to Norton for class at noon.

But even with a loaded schedule, Rubin made time for fun. The first photo shoot for Rubin Douglas took place with some college buddies over beers.

“My friends were always there to bail me out of whatever I had gotten into,” Mr. Cronig said while laughing. Starting a business can be a process of continually biting off more than can be chewed, but a solid group of comrades made the load a bit easier to swallow. “I really needed my friends throughout the whole process and I still need them. That includes not only my college friends but my friends from Charter School. You can’t imagine what a family it is. I hated school until I got there. Now I have that family to help push and pull me along.”

By the time Rubin received his bachelor’s degree in economics, he was envisioning a new project. He returned home with a burgeoning business, but wanted to open up a mid-range line of watches for a different market.

He began working with scrimshander Tom DeMont of the Edgartown Scrimshaw Gallery. Tom sold his scrimshaw artwork — intricate pictures etched into animal bones, teeth and tusks, originated by whalers in the 18th century. The pair adopted Rubin’s main objective: “I’ve always tried to bring in materials that are untraditional in the watch world.” Previously, that had meant unique silver and gold engravings and the Japanese art of mokume. With Tom, the solution was scrimshaw — very Vineyard and endlessly eye-catching, according to Mr. Cronig.

“We didn’t even know if it could be done. A scrimshaw dial has to be thick enough to allow for the carving to be done, but thin enough to fit in a watch,” he explained. “We made 10 and put them out in Tom’s store.” They all sold immediately. “Then we made another 10. Then 100. There’s a wide demographic that’s attracted to a hand-scrimshawed, locally hand-assembled watch that costs under $1,000.” It’s been that way ever since.

But Mr. Cronig did not plan on opening his own retail store. He was a wholesaler, and Tom’s shop in Edgartown was a perfect outlet for local sales. But when Tom died unexpectedly of a stroke last December, his family sold the Edgartown Scrimshaw Gallery.

Rubin’s website, called Vineyard Time, dedicates the homepage to Tom. It reads “A tribute to Tom, every watch in dedication.”

“I opened this store in Tom’s honor,” Rubin said. “I wanted to keep selling our watches. Tom’s family encouraged me. I decided to go for it,” he said.

Rubin’s new store, AquaNaut, is on Main street in Vineyard Haven. He set up the store in just three months and opened in time for summer. He admits, “I’m just getting out of the daze now.”

As Mr. Cronig placed a pair of scrimshawed billiard balls into a glass case on a breezy Sunday, a crew of young sailors walked in and browsed the showcases. Two of them left with much-needed new knives, the words “great deal” spilling from their mouths.

Then a tall man walked into the shop with his wife and asked, “How much is the compass rose watch in the window?”

The watch cost $985. Mr. Cronig and his costumer conversed in watch language for all of two minutes before the “I’ll take it” came and the watch was wrapped up.

As the couple left and another pair poured in, Rubin checked his watch. It was just after 2:30.

“Business is good today!”