1. LA PAZ, MEXICO

The Cortez Club, a PADI IDC center in Baja, Mexico, and Fun Baja, at the Costa Baja Resort & Marina, can take you diving with California sea lions — and the instructors will satisfy your curiosity about these charismatic creatures.

Take the sea lion distinctive specialty course, and learn about the animal’s 11-month gestation period, how it hunts, and more (such as differentiating between a seal and sea lion). It’ll make your encounters with the 400 sea lions of Los Islotes, 27 miles north of La Paz, more meaningful. In this area, June and July is the birthing season, immediately followed by mating season.

In October, the pups have matured enough to play with divers, often swimming loops around them, and by December, they’re so confident that they bite fins and snorkels. cortezclub.com funbaja.com

2. ISLE OF SHOALS, NEW HAMPSHIRE

“They find you; you don’t need to find them,” says Jay Gingrich, owner of New Hampshire’s Portsmouth Scuba.

He’s talking about the harbor and gray seals that inhabit Duck Island, the most northeasterly of the Isle of Shoals, 7 miles from shore. Gingrich estimates that in the summer months, divers visiting the area encounter 100 or so seals, and in winter, the numbers can be 
as many as 10 times greater.

The animals winter in the region, taking a break from the chillier waters of the Gulf of Maine.

“They’re intelligent,” he says. “After eating and sleeping, entertainment is highly regarded — and that’s where we come in.” portsmouthscuba.com

3. MONTEREY, CALIFORNIA

In the Monterey area, divers don’t need a boat — they can shore-dive with California sea lions and harbor seals. James Vincent, owner of Aquarius Dive Shop, recommends taking the plunge at night at Breakwater Cove to guarantee harbor seal encounters.

“We had one follow us for 45 minutes — it was using our lights to hunt rockfish and octopuses,” he says.

It’s an experience that’s happened on all of his summertime dives at the site. The harbor seals — the smaller of the two species — are much more interactive, even during the day. They nibble on drysuit gloves and just about anything else they can fit in their mouths, whereas sea lions are known for barreling in for quick swim-bys before barreling away. aquariusdivers.com

4. HORNBY ISLAND, BRITISH COLUMBIA

“We were surrounded by 70 or 80 sea lions — it was unreal,” says Shane Craver, master scuba diver trainer at the Edge Diving Center.

The shop in Vancouver, British Columbia, regularly visits Hornby Island, about 118 miles north, known for year-round diving with Steller and California sea lions, plus Puget Sound king crab, 7-foot-long lingcod and more.

The rookery is a five-minute boat ride from Hornby Diving Lodge, where the group stays. The site itself is only about 40 feet deep, giving divers more than enough time with the sea lions. Craver admits that the number of pinnipeds can overwhelm, but he reminds divers to respect the sea lions and give them distance.

“They don’t always know when to stop playing,” he says. “If they try to bite you, give them your elbow, then they’ll ease up.” edgediving.com

5. SAN DIEGO, CALIFORNIA

In the greater San Diego area, June and July is harbor seal mating season, and La Jolla Cove is the place for surefire encounters.

“They are much louder that time of year,” says Rocio Gajon, instructor at Ocean Enterprises dive center. “I’ve gotten too close and heard this amazingly loud, unstoppable bark — they won’t attack, but they will warn you.”

The site itself, part of the La Jolla Ecological Reserve, is a shore-access kelp forest. The area is also great for nondivers who want to see seals and sea lions.

Says Gajon, “You can stroll the boardwalk and still have encounters — no snorkel necessary.” oceanenterprises.com

6. GALAPAGOS ISLANDS, ECUADOR

“All the dive sites in the Galapagos have
 sea lions year-round,” says Wayne Hasson, president of the Aggressor fleet, including those visited by Galapagos Aggressor III.

The islands, 600 miles off the Ecuador coast, are home to both fur seals and Galapagos sea lions — both of which are protected from touching by law.

“They’re always on the shoreline, and you never know when they’ll get in the water.” Hasson says he eyes their hind legs as they lounge on rocks to see if they’re readying for a swim. But even then, he’s usually surprised. “They tend to sneak up on you.”

And then playtime is on. Several sea lions have offered him a starfish, and one even stole his safety sausage. “They love to clown around, and if they get a piece of your gear, forget about getting it back.” Hasson has also had encounters with the males, or bulls. “They can be 700 pounds, and will bark at you while they’re on the bottom, sitting as if in a chair.” The encounters can vary wildly, but one thing stays the same — even after divers swim with enormous whale sharks and schooling hammerheads, it’s the sea lions that keep them talking long after their gear has dried. aggressor.com

7. KAUAI, HAWAII

“I first dove Ni’ihau 28 years ago,” says Walt 
McCoy, general manager of Seasport Divers, 
a Kauai-based scuba center. “That night, we anchored between Ni’ihau and Lehua
rock, and caught fish and grilled them. The 
next morning, we were greeted by two monk 
seals eating leftovers off the grill.” And while 
McCoy hasn’t had seals board a boat recently, he says Ni’ihau remains the best spot
 for seal encounters.

Seasport Divers visits this satellite island May through October, and find seals about 75 percent of the time. It’s a species he finds especially poignant
to swim with because it’s endangered — only 1,100 remain — and it’s one of two mammals endemic to the Hawaiian Islands. seasportdivers.com

8. SANTA BARBARA, CALIFORNIA

As soon as the boat anchors, a hillside full of seals comes swimming,” says Chris Callahan. The manager of Truth Aquatics dive shop is talking about the harbor seals and sea lions at a dive site called the Rookery on Santa Barbara Island.

Truth Aquatics, based in Santa Barbara, runs day trips to the Channel Islands, including San Miguel, Santa Barbara and Santa Cruz; weather determines which spot they’ll visit.

Callahan says that San Miguel boasts higher numbers of seals — and it’s the only island with resident northern elephant seals — but Santa Cruz offers more-reliable conditions. truthaquatics.com

9. FARNE ISLANDS, ENGLAND

William Shiel has spent the past 20 years diving and operating boat tours to the gray seal colony — some 5,000 strong — of Longstone. It’s one of the Farne Islands found
off the east coast of England just south of the Scotland border.

This wildlife sanctuary is known for sheer limestone cliffs, sightings of puffins, arctic terns and 288 other bird species, and a seal-visitation season extending July to November.

Shiel’s advice: Be patient. “Build the seals’ confidence,” he says. “When you’re underwater, don’t make sudden movements, and they will get a bit braver and a bit braver. Next thing you know, they’re swimming alongside you.” sunderlandscubacentre.com

10. MARLBOROUGH SOUND, NEW ZEALAND

It’s snorkel only, but New Zealand’s Marlborough Sound, found on the northeast tip of Southern Island, is among
 the most picturesque places for a seal encounter.

Green, craggy hillsides surround turquoise water and a shoreline dotted with puffins and other marine birds. March through November, the local outfitter Nine Dives offers day trips with New Zealand fur seals. ninedives.co.nz

KEEP LEARNING

What’s the difference between seals and sea lions?

We’ll admit it — we get confused about this one sometimes too. Everything you need to know about the difference between seals and sea lions is in the ears: sea lions (like the one shown above) have visible ear flaps; seals do not. Sea lions have large flippers, bark loudly and “walk” on land; seals have small flippers, wriggle on their bellies on land and are faster in the water.