Have a steady whole sail breeze at WSW. Steered NW. Saw several humpbacks and finbacks. At 9 AM, saw the land, the coast of Asia near Kamchatka. Steered for the land until sunset. Saw 6 ships in shore. The sun sets clear and beautiful. The land mountainous and covered with snow.

So wrote Frederick Olney, third mate of the New London whaler Merrimac, on August 4, 1845 in a journal he kept aboard the whaling ship. Donated to the New London Maritime Society and transcribed by dozens of “citizen scriveners,” Olney’s 156-page journal chronicles the Merrimac’s three-year journey, one of more than 1,100 such voyages from Connecticut’s “Whaling City” on the Thames.

Many of us are both captivated by the maritime adventure of whaling yet repelled by the mass killing of whales for their body parts—oils, bony cartilage and waxes—used widely in the past in consumer goods like cosmetics and perfumes, lubricants and candles (and still being sold in some parts of the world, according to the International Whaling Commission).

The good news is that since the U.S. Marine Mammal Protection Act of 1972 and later conservation efforts, including a 1986 global whaling moratorium, whale populations are recovering from the 19th- and early 20th-century slaughter.

Even better, you don’t need to voyage to Kamchatka to see humpbacks, finbacks and other species. At the mouth of Massachusetts Bay, just east of Boston between Cape Cod and Cape Ann lies Stellwagen Bank National Marine Sanctuary, New England’s only national marine sanctuary and an increasingly popular site for whale-watching and whale research.

This 842-square-mile plateau, first mapped around 1854 by U.S. Navy Lt. Henry Stellwagen for the U.S. Coast Survey, is visited every year by humpbacks, fin whales, baleen whales, dolphins and porpoises.

Upwelling, when warmer surface water is replaced by cooler, nutrient-rich water from below, turns Stellwagen Bank—at an average depth of 100 to 120 feet—into a picnic table for the marine food chain of plankton, krill, fish and whales.

On a recent trip hosted by New England Aquarium, we boarded the Aurora at Boston’s Central Wharf during a rainstorm. With four- to six-foot swells predicted, some would-be passengers bailed out.

Seated in the Aurora’s enclosed section during the hour-long cruise to Stellwagen Bank, we peered at the docked lightship Nantucket, the Logan Airport Tower, Fish Pier, the Conley Container Terminal and the harbor islands, described by our naturalist-guide, Colin Greeley. We passed historic Boston Light, opposite the hilly town of Hull, and Graves Light, 11 miles out.

Flat screens displayed informative slides, along with multiple-choice questions such as: “What is the average width of a humpback whale’s fluke?” (Correct answer: 12 feet.)

Past the harbor, there was a gentle roll; the rain stopped by the time we reached the bank. The Aurora, now slowed, tipped forward and back and side to side, items sliding off tables as we turned into the waves and people doing the classic “drunk walk” as they made their way out onto the deck.

We scanned the waves for spouts and for petrels flying above schooling fish. Greeley suggested we look for “body parts”—that is, flukes (or tails, like the “whale-tail fountain” in New London’s Parade Plaza) and dorsal (back) and pectoral (side) fins.

The trip’s stars? Humpbacks—bigger than a city bus, measuring roughly 50 feet long and weighing 30 tons or so. Humpbacks are identified by their long, white pectoral fins and narrowing heads with knobby hair follicles. The underside of each individual’s fluke, we learned, has a unique white-on-black pattern (except when there are no white markings), enabling researchers to identify and name the whales.

First to be spotted was a humpback named Nile with a calf. Next, only a few dozen yards from the boat, another female humpback, Music, repeatedly flapped a pectoral fin, “double flipper-flapped”—waving both white fins above the water while on her back—and breached, or arced out of the water three times.

Humpbacks are known for breaching, believed to be a form of communication. Last Memorial Day, a family out boating near Race Rock filmed a humpback breaching the waters just west of Fishers Island, and their video made the rounds online and on the TV news.

While humpback populations are in the tens of thousands, the North Atlantic right whale—hunted both for its quantity of oil and tendency to float after being killed—is critically endangered, with fewer than 440 remaining, according to the Ocean Conservancy. A positive note: Greeley said he had observed Canada-bound right whales in April and May.

The next day, I went from bustling Boston to sandy Provincetown at the tip of Cape Cod. Based at the Seaport World Trade Center in Boston’s redeveloped Seaport District, the Bay State ferry scooted across to Provincetown in about 90 minutes.

A few commercial fishing vessels still dock at Provincetown’s MacMillan Pier, but it is mostly given over to charters, souvenir booths, outposts of the nonprofit Shark Center and Center for Coastal Studies—keeper of the Gulf of Maine Humpback Whale Catalog—and whale-watch boats including the one I rode: Dolphin X of the Dolphin Fleet, “Originators of the East Coast whale watch.”

Our guide and naturalist, Dennis Minsky, quipped that the boat’s front viewing area would open “when we get to whales—the animal, not the country.” On a poster, he pointed to the species we were likely to see: finbacks, humpbacks and minkes (a baleen species just 30 feet long). In thousands of trips, “I have never seen a sperm whale,” he said, due to their preference for remote waters.

Though the “population explosion” of gray seals has attracted great white sharks, more than 250 of which have been tagged around Cape Cod, it hasn’t lured orcas, he noted.

Never out of sight of the 252-foot Pilgrim Monument, for over an hour after reaching Stellwagen Bank the whale viewing was continuous. The final tally: roughly 20 finback whales—a sleek species second in size only to the rarely seen blue whale—and 10 humpbacks, including Glow, Anvil, Ember and Etch-a-Sketch, and one calf.

Several times, humpbacks poked their “noses” out to feed, which they do by swallowing quantities of fish-filled water, pleated throats expanding, then pushing the water out through their baleen plates. One humpback wiggled up in a sort of spyhop, the term for a vertical look-around.

“All these whales have grown up around whale-watch boats,” Minsky explained.

Both of the tour companies are members of the Whale Sense program, promoting responsible whale-watching and educating the public about the main threats to whales: vessel strikes, fishing-gear entanglement, ingestion of plastic and underwater noise.

After turning the boat so that everyone aboard had the best view of the many whales, the activity and presumably the feeding ceased. This was whale-watching’s “ebb and flow,” according to Minsky. And unlike Frederick Olney, we had experienced it over three hours, not three years.