Diving San Carlos, Mexico: A Weekend Escape from Tucson

Ben Lair   Jul 16, 2025

Closer Than You Think: The Fantastic Diving of San Carlos, Mexico

Living in Tucson, we’re blessed with dramatic landscapes and endless sunshine. But for those of us with saltwater in our veins, the urge to explore the ocean is a constant companion. The good news? You don’t need a plane ticket to an exotic, faraway land to experience world-class diving. Just a short, scenic drive south lies the stunning Sea of Cortez and the vibrant coastal town of San Carlos, Sonora, Mexico—our favorite backyard ocean playground.

San Carlos is the ultimate accessible dive destination for the 72 Aquatics community. It's a place where you can leave Tucson in the morning and be watching the sunset over the water that same evening, ready for a weekend packed with incredible underwater adventures. Whether you're a new diver looking to build confidence or a seasoned veteran eager for unique marine encounters, San Carlos delivers in spectacular fashion.

The Sea of Cortez: The World's Aquarium

The legendary ocean explorer Jacques Cousteau famously called the Sea of Cortez "the world's aquarium," and he wasn't exaggerating. This narrow sea, tucked between the Baja California Peninsula and the Mexican mainland, is a biological marvel. It's a unique transition zone where temperate Pacific waters meet warmer, tropical currents, creating a rich mixing bowl of nutrients that supports an explosion of life.

The diving in San Carlos showcases this diversity perfectly. The underwater landscape is a dramatic mix of rocky reefs, sheer walls, hidden coves, and towering pinnacles that rise from the depths. These structures are draped in colorful sponges, gorgonians, and soft corals, providing shelter for a staggering variety of marine creatures.

The Main Event: Diving with the Sea Lions of Isla San Pedro Nolasco

Let’s be honest: the number one reason divers flock to San Carlos is for the unforgettable experience of interacting with the California sea lions at Isla San Pedro Nolasco, often just called "Seal Island." This rugged, offshore island is home to a massive, thriving colony of hundreds of these curious and charismatic marine mammals.

Diving here is pure, unadulterated joy. As soon as you descend, you’re greeted by the sleek, torpedo-like shapes of pups and juvenile sea lions. They are the epitome of playful. They'll zip past your mask, barrel-roll around your bubbles, and playfully tug on your fins. They aren't just tolerant of divers; they seem to genuinely enjoy the interaction. It's impossible not to surface from a dive at Seal Island without a massive smile on your face. This is an experience that creates lifelong memories and reminds us why we fell in love with diving in the first place.

Beyond the Sea Lions: A Tour of Premier Dive Sites

While the sea lions are the stars, the supporting cast of dive sites around San Carlos is equally impressive.

• Martini Cove: Known for its "aquarium-like" conditions, this is a fantastic site for all skill levels. It's often teeming with massive schools of fish, including brilliant yellow-tailed surgeonfish, grunts, and snappers. Look closely in the crevices for moray eels, lobsters, and sleeping whitetip reef sharks.

• Eagle Rock (Roca del Águila): This site features a series of impressive underwater pinnacles that attract a huge amount of life. It's a great spot to see larger schools of fish and admire the dramatic underwater geology.

• The Wrecks of San Carlos: For those who love exploring sunken treasures, San Carlos has two accessible wrecks. The Presidente is a former ferry, while the Albatun is a tuna boat. Both were intentionally sunk to create artificial reefs and are now encrusted with life, providing homes for countless fish and invertebrates.

What You'll See: A Blend of Worlds

The fish life in San Carlos is a fascinating mix. You'll find classic tropical species like dazzling king angelfish, colorful parrotfish, and intricate butterflyfish swimming alongside more temperate species like giant sea bass and various types of rockfish. The macro life is equally rich, with nudibranchs, shrimp, and blennies hiding among the rocks for sharp-eyed divers.

Keep an eye on the blue as well! It's not uncommon to spot dolphins on the boat ride out or even encounter majestic manta rays or pods of whales during their migration season (typically in the winter and spring months).

Plan Your San Carlos Escape with 72 Aquatics

Because of its proximity and the quality of diving, San Carlos is a regular destination for weekend trips organized by 72 Aquatics. Joining one of our group trips is the easiest way to experience this fantastic destination. We handle the logistics so you can focus on the fun, the community, and the incredible diving.

When to Go: Diving is excellent year-round, but conditions change. Summer (July-October) brings the warmest water, often reaching into the mid-80s (∘F), which is perfect for attracting more tropical species. Winter and Spring (December-May) offer cooler water but often have stunningly clear visibility and are prime time for migrating whales.

Your next great dive adventure doesn't have to be halfway around the world. It’s right next door. Stop by the shop to chat with us about San Carlos, check our travel section or our dive calendar for the next trip, and get ready to discover the underwater wonders of the Sea of Cortez.