Once-in-a-lifetime events can happen with serendipity.

So it was for Frank Carpenter one morning in June 2004 when he was accompanying a 92-year-old woman from New York on a private tour of Kealakekua Bay, Hawaii island.

Dolphins are commonly spotted there, but on that particular day he estimates 200 of them were swimming around their kayak.

“We stopped paddling, got into the water and floated in silence for 10 minutes, just taking it all in,” Carpenter said. “It was magical — one of the most incredible experiences I’ve ever had. As for my guest — her face was full of wonder and pure joy.”

Carpenter and his best friend, Brock Stratton, had just bought Kona Boys, an outfitter that’s celebrating its 20th anniversary this year (they run it as co-CEOs). It is one of only three companies that hold a permit from the Department of Land and Natural Resources’ Division of State Parks to operate kayak tours in Kealakekua Bay, which was established as a Marine Life Conservation District in 1969 and listed on the National Register of Historic Places in 1973.

“We’ve set a self-imposed limit of 10 kayak rentals a day to do our part to prevent excessive recreational use of the bay,” Carpenter said. “We don’t want to see overcrowding there; that threatens the balance in nature and the health of the bay.”

Up to 12 people can join each of Kona Boys’ two guided tours to the bay. If time permits, the Morning Magic Kealakekua Bay Kayak and Snorkel Tour is preferable because it departs at a cooler time of the day, includes a hearty lunch and allows two hours of snorkeling time (compared with about one hour for the shorter midday tour).

After checking in and picking up snorkeling gear, participants drive to Napoopoo Pier, where their guide and two-person kayaks await. It’s a leisurely 1-mile, one-hour paddle to the north side of the bay; along the way, sharp-eyed paddlers are likely to spot dolphins, turtles, flying fish and, from November through March, breaching humpbacks.

“We often have people on our tours who’ve never paddled before,” Carpenter said. “But Kealakekua Bay is generally very calm, and it takes minimal instruction for most of them to get a feel for paddling.”

Paddlers beach their kayaks, then head into the water for close-up looks at tropical reef fish, coral gardens, sea turtles, eagle rays, octopuses and eels. Afterward there’s ample time for lunch, exploring the shoreline and “talking story” with the guide about Kona’s history and lifestyle before paddling back to the launch site.

It’s great fun in a gorgeous setting, which Carpenter hopes will inspire participants to respect and protect ocean resources wherever they live or visit.

He has long held an affinity for the water. Born in Germany to a military family, he was raised in Idaho, Montana, Arizona and California. His aunt and uncle moved to the Big Island in the early 1970s, and he visited them as often as possible.

“I grew up around lakes and rivers, and I was always into the outdoors,” Carpenter said. “When I came to Hawaii, I was blown away by the clarity and warmth of the water. A lifestyle that included surfing and wearing a T-shirt and board shorts most of the day was really appealing to me.”

In 2000, after earning a degree in English from Northern Arizona University, Carpenter was doing business development for a startup internet venture in Los Angeles. He and a few friends went on a surfing trip to Kona that year which changed the course of his life.

“I realized I was playing the right game but running toward the wrong end zone,” he said. “I went back to L.A., quit my job and was back in Kona less than a month later. I started working for Kona Boys the day I arrived; they told me if they liked me after I worked a week for free, they would hire me.”

From a little kayak rental shop, he and Stratton have built Kona Boys into a thriving business. They both have two young boys whose playtime is often spent at Kealakekua Bay swimming, surfing and paddling with their dads.

“It takes time to become established on the Big Island, but we’ve shown that we’re committed to giving back to the community,” Carpenter said. “Now that we have boys of our own, we have a new perspective on Kona Boys. It’s great to share our passion for the ocean with our sons and to watch them grow up as true Kona boys.”

Captain Cook Monument

A 27-foot white obelisk on the shore of Kealakekua Bay honors Capt. James Cook, who is credited with discovering the Hawaiian Islands. On Feb. 14, 1779, he was killed in a skirmish with Hawaiians close to where the monument stands. It was erected in November 1874 by, as its inscription reads, “some of his fellow countrymen.”

On Jan. 26, 1877, Hawaiian Princess Miriam Likelike deeded the 5,682-square-foot parcel to England for $1 with the stipulation that it be used “to keep and maintain … a monument in memory of Captain Cook.” So step on that land and you’ll be on British soil.

Cheryl Chee Tsutsumi is a Honolulu-based freelance writer whose travel features for the Star-Advertiser have won several Society of American Travel Writers awards.