NORTH KINGSTOWN — High summer has come and gone. Back-to-school sales are abundant, and college students have returned to out-of-state campuses.

But there is summer enough left that the line at the Quonset Point pier awaiting this Rhode Island Bay Cruises boat tour of 10 lighthouses and Newport Harbor is thick with ticket-holders on a beach-perfect midweek day.

Baseball caps are quickly grasped as the Millennium Ferry sets off for 90 minutes of viewing the Ocean State from the waves. Summer air that a moment before clung like a mohair sweater lifts with the bright and cool wind created by the sendoff of the three-level, 400-passenger sightseeing catamaran.

Summer may be waning, but it’s not time yet to make good on the “See You in September” promise, and these boat tours offer ocean adventure into October’s Columbus Day weekend.

“This is the first year of a permanent schedule,” said owner and operator Charles A. Donadio Jr., of Narragansett. “We had 50 dates. Next year, we’ll have 70 or 80.

“It’s a service that adds to what Rhode Island is all about.”

Parking for the lighthouse cruise is free, and some who awaited the 2 p.m. departure tailgated in the grassy lot, getting some sun. Others stepped off buses with group tours.

All of them were waiting for a 30-mile excursion that brushes past the coastline of North Kingstown, Narragansett, Jamestown and Newport, a swing through Newport Harbor and the Bay-side view of seaside mansions mostly seen from afar.

Arthur Strauss, of Narragansett, narrates these trips, introducing tour-goers to the 10 lighthouses — or what remains of them — sounding a little surprised himself that so many beacons were built within this small area.

He sounds similarly thrilled with the 10 islands, referring to them as if they were Bay starlets, some obscure, others world-famous.

His sense of admiration for this checkerboard of lighthouses and land is both genuine and infectious, for in-staters and out.

“People love it,” he says. “We’re so landlocked, this is a chance to see things from the water.”

For non-boaters, it is indeed a perspective far different from either bridge or roadside.

STRAUSS IS the face of these tours because the captain and the mate are tucked away in the quiet, cool wheelhouse piloting the ferry, their view of the water ahead staggering in its beauty. But they are there to concentrate so that the tourists can relax and experience the Rhode Island scenery from their own perspective.

Strauss says tourists tend to arrive with tales of parents stationed at Quonset or Newport, grandfathers who fished these waters, or childhoods spent swimming along this coast. There’s an endless fascination with lighthouses, he says, “and everyone has read or heard about Newport.”

So they leave him with family sagas, or question his facts, and he accepts additions and challenges to his narration with good-natured and audible debates.

“A sense of humor is important,” he says.

The narration is mostly historical, with a little voyeurism tossed in when yachts appear in Newport Harbor and speculation of ownership rumbles. Strauss points toward Hammersmith Farm, “where Jackie Bouvier and Jack Kennedy had their wedding reception for 1,200 people,” and Clingstone, the house built on a rock in Narragansett Bay that was the subject of a recent newspaper article Strauss pulls from his case.

As he reminds tourists that drinks and snacks are available in the ferry’s galley, a Bostonian taking in the Newport scenery reflects to no one in particular, in a deep and guttural voice:

“All the money.”

“I’VE ALWAYS been fascinated with lighthouses, so we figured, why not take the tour,” said Perry Myers of Hanover, Pa. (“You’ve heard of Utz potato chips,” he says as a way of introducing his hometown.)

It would have been nice to tour one of the lighthouses he didn’t know existed until he boarded this boat, but his family vacation was about to end, he said, and he had yet to sample a clam cake. There didn’t seem to be enough time to experience the Ocean State, especially now that the boat tour had opened up unusual new places to explore.

“We live five miles from Gettysburg. That sort of stuff we see every day,” he said of the Civil War battlefield, with the attitude a Rhode Island native might cast upon the I-see-it-often ocean. “It’s not unique to us.”

Lined up next to each other were the Hutchins sisters, of Scituate — Hayley, 16, Sarah, 15, and Maggie, 12 — with their friend Danielle Roth, 14, of Coventry. The Hutchins girls said the boat trip was their mom’s idea, and they were not sure it would have appeared on their day planner had it not been suggested to them. They brought along novels, just in case the tour of their home-state coastline fell a little flat.

But halfway through the tour, they smiled wider than at the beginning. It was better than she expected, said Hayley, still clutching her closed-up novel.

IF THESE GIRLS needed a topic for a Rhode Island history project, they could use this tour as background, as it offers an up-close look at intact lighthouses, and others altered by man and storm. They include Poplar Point, Plum Beach, Dutch Island, Whale Rock, Beavertail, Castle Hill, Lime Rock, Goat Island, Rose Island and Conanicut Island.

Then there are the islands to document: Fox Island, Dutch Island, Jamestown, Aquidneck Island, Goat Island, Rose Island, Coasters Harbor Island, Gould Island, Hope Island and Prudence Island.

And the Jamestown and Newport bridges are seen from a unique angle.

“Kids, get ready,” Strauss says with excitement. “We’re going under the bridge.”

“OUT-OF-STATERS love Rhode Island,” says Strauss, 73, of what he has discovered during these trips. A retired state employee, he has narrated local history aboard other vessels and buses, so Donadio asked him to make the transition to the ferry.

Donadio started the high-speed ferry to Martha’s Vineyard in 2003 and said he tested the lighthouse-cruise idea three years ago. When the price of fuel shot up over the winter, he decided to put the cruise to work for him, adding it to the schedule three days a week, in between runs to Martha’s Vineyard.

“The sites are here, and people will still go out to see them, despite the economy,” he said.

According to his statistics, he said, 55 percent of those taking the lighthouse cruises are from Rhode Island, while fewer than 10 percent of those taking the ferry to Martha’s Vineyard are state residents.

Stepping off the lighthouse cruise was Mary Ann Pires, of Greenville, S.C., who was spending the August week visiting daughter Carrie, of Norwood, Mass. They spent the week in Watch Hill, and came across the ferry brochure in a local office.

Pires said the Bay boat ride was so cool and refreshing, compared with what she knows the air feels like back in South Carolina at this time of year.

Her daughter said she felt the tour “really showed me Rhode Island from a different angle. I have been to the state many times, and love it, but had never seen these attractions.”

Her mother liked it too, but she enjoyed something else as well.

“I like the people of Rhode Island,” she said. “They’re so friendly.”

The tour departs today, tomorrow and Wednesday at 2 p.m. and returns at 3:30 p.m.. Thereafter, through Sept. 30, tours will depart Saturday and Sunday at 1 p.m. and return at 2:30 p.m., with the addition of Thursday, Sept. 25. On Oct. 4, 5, 11, 12 and 13, cruises will depart at 1 p.m. and return at 2:30 p.m.

Parking is ample and free. Portions of the boat are air-conditioned, and drinks and snacks are sold. The cost is $25; $22 for seniors 60 and older; $14 for children 2 to 12; free for children under 2.

The departure location is at the end of Route 403 east, which merges into Roger Williams Way at Quonset Point. Reservations are suggested. Call (401) 295-4040 or check www.rhodeislandbaycruises.com. Save the Bay has also offered lighthouse tours this summer. The first one was in August, the second, on Sept. 20, is sold out and the third is scheduled for Oct. 4. The tour will depart from the Save the Bay Center in Providence at 9 a.m. For more information call (401 272-3540 or check www.savebay.org

afleming@projo.com