When Royal Caribbean Cruises’ Jewel of the Seas comes to Rockland it will be the first stop in a seven-day roundtrip cruise from Boston and a big step forward in boosting Midcoast tourism.

The cruise, departing Boston October 3, has a planned itinerary of stops in Bar Harbor, Saint John, New Brunswick, Halifax, Nova Scotia. This just could be the turning point, after which, the tourism landscape of Midcoast Maine may never be the same.

Rockland plans a big welcome to the ship, which docks on October 4. The arrival of large cruise ships is yet another sign of the renaissance of Rockland, a town that first made the map with its limestone quarry, according to Frank Isganitis, secretary of the Chamber of Commerce for Penobscot Region. The town also was known for its Birdseye cod processing in the 1940’s and 1950s, according to Isganitis, and has seen smaller cruise ships come and go-ships from American Cruise Lines and American Canadian Caribbean Line, for example-but not one with the size and sparkle of the 2,500-passenger Jewel of the Seas.

The businesses of Rockland are so excited that the town plans to close its Main Street for the day when the 962-foot long Jewel is in port, allowing passengers to stroll Rockland’s restaurants, shops and, of course, the Farnsworth Museum.

This docking testifies to the emerging trend to market the shoreline’s shoulder season, when the weather is still warm and the tourists enjoy fall foliage. “We have no experience with megaships,” says Frank Isganitis, secretary of the Chamber of Commerce for the Penobscot Region. “If we are forthright with the industry, it’s to say that only on our shoulder season we accommodate tender boats.”

Fall foliage draws the tourists in this shoulder season. “Rockland and Camden realize that it’s important to have a diverse economic mix,” says Amy Powers, director of CruiseMaine. “You don’t want to throw all your eggs in one basket, especially in this economy.”

There are between 400 and 500 moorings in the Rockland harbor to accommodate boats; also, an intricate map of channels and lanes have long been created to protect lobster traps as well as the ferry boats travelling Vinalhaven, Matinicus and North Haven. Yet the potential to grow a market segment for the local and regional economy is not lost on the region’s residents.

Day trips for the Jewel of the Seas’ passengers range from kayaking to wine tasting, fly fishing to day sailing. The ship plans to offer four excursions: “Best of Midcoast Maine and Lobsterbake,” “Camden and Mount Battie Summit,” and “Owl’s Head Transportation Museum and Lighthouse.” Bettina Doulton will welcome visitors arriving aboard Jim Gamage’s “All About Trolly”-a short train ride from Rockland out to Cellar Door Vineyard. The experience, says Doulton, will offer a “unique perspective of Maine-come by cruise ship to visit a winery.” Wines include Amarosa, Blue Lobster Blue and Casa Blanca , with sandwiches and complementing tastings.

Furthermore, Royal Caribbean prides itself on an active passenger manifest, but some land-based activities are definitely not for the floundering out-of-shape tourist. Mark DiGirolamo, owner of Breakwater Kayaking and Company, hopes that a few arrivals will be up to the challenge. “They may have the motivation,” says a seasoned DiGirolamo, “but they also need to put in the effort.” Kayakers will put in right in the harbor.

And then there’s the promise of fishing. Super Fly Charters of Warren plans to welcome disembarking cruise ship passengers with fly and light tackle, spinning gear fishing for striped bass, blue fish and blue fin tuna only 15 miles away.

Next year, megaships are inquiring into the Midcoast destination. Next month, Rockland will just be getting a tame test of possible crowds to come.