A look at alternatives to overcrowded destinations.

Maui’s Molokini Crater: Like snorkeling in a packed aquarium

(David Fleetham/Alamy Stock Photo)

According to Hawaiian legend, Maui’s Molokini Crater is the tail of a lizard whose body was cut in half by the goddess Pele. I imagine in the future, the story will be that this half-sunken caldera was engineered by the Hawaii Tourism Authority to resemble a set of arms thrown wide open toward Maalaea Bay, welcoming ships full of tourists. Nearly half a million visitors snorkel and scuba dive at the crater each year, lured by the promise of calm, crystalline waters with visibility often exceeding 150 feet. Once used for bomb practice by the U.S. military, this designated Hawaii Marine Life Conservation District is now home to some 250 fish species and 38 coral species. Snorkeling there, protected from wind and waves, you feel like you’re in an aquarium, albeit one packed with other observers. At least half a dozen boats, some with as many as 140 passengers, moor off the crescent-shaped crater. For every rainbow-hued parrotfish chomping on cauliflower coral, there is at least one pasty skinned snorkeler wrapped in a yellow flotation belt distracting from the peacefulness under the sea.

If you do go, avoid the boats that look like floating water parks — I would recommend Sail Maui’s Paragon II, which caps trips at 38 guests — so you’ll have fewer snorkelers near you in the water. Go during whale season (December through May) and you might even see some big fish during the breezy 2½ -mile boat ride.

Excursions to Molokini Crater with Sail Maui cost $125 for adults; 808-495-0879; sailmaui.com.

Puu Kekaa and Honolua Bay: Room to roam

(Debra Behr/Alamy Stock Photo)

For a snorkeling experience that feels more “Blue Planet” than “Life Aquatic,” rent equipment and head to Puu Kekaa on the island’s West Side. This lava promontory, also known as Black Rock, is at the north end of famous Kaanapali Beach, in front of the Sheraton Maui Resort & Spa. Entry from the shoreline is easy, but this is a DIY snorkeling experience, so check beach safety signs. Go early, before the afternoon trade winds pick up, and snorkel along the edge of the rock. You’ll reach a vertical wall about 30 feet deep, where you’re likely to see sea turtles, spotted eagle rays, and a sandy bottom blanketed in starfish and urchin. In season, you might also be serenaded by singing humpback whales.

Fish geeks who crave more context can book a snorkel trip to Honolua Bay. (I’d recommend the Pacific Whale Foundation’s eco-charters.) Located on the northwest side of the island, the bay is part of the Honolua-Mokuleia Marine Life Conservation District and is dense with healthy coral and schools of reef fish. High rock cliffs keep the waters mellow and clear most of the year (winter conditions are normally too rough for boats and snorkelers) and are prime for first-time snorkelers.

An encounter with a sea turtle is all the more special when it’s one-on-one, which is often the case here and at Black Rock (in fact, turtles aren’t found at Molokini Crater); just remember to keep the recommended 6-to-10 foot buffer around the protected creatures.

Excursions with the Pacific Whale Foundation cost $125 for adults; 800-942-5311; pacificwhale.org.

Murphy is a writer based in Boulder, Colo. Her website is jenrunsworld.com.

More from Travel:

While tourists pack Gaudí’s famous Barcelona church, visit this serene and stunning site

Planning a New York City trip? Ditch Central Park for this less crowded option.

This Yellowstone geyser and its surroundings are worth a visit. And, no, it’s not Old Faithful.