Bat Islands Bull Sharks · Remote · Raw Pacific
The only reliable bull shark dive in Costa Rica. Deep inside Santa Rosa National Park, the Bat Islands deliver one of the most adrenaline-charged underwater experiences in Central America.
Costa Rica's Most Thrilling Dive — and Its Most Remote
Further north than the Catalinas, the Bat Islands sit deep inside Santa Rosa National Park — one of Costa Rica's oldest and most protected marine reserves. This remote archipelago of volcanic rock formations features steep drop-offs, pinnacles, and variable currents that concentrate large pelagic species year-round.
Sites like Big Scare have earned international reputations for their bull shark encounters. These are not staged or baited dives — this is wild, open-ocean diving in a protected marine corridor where the ecosystem is intact and the animals behave naturally. That's what makes it extraordinary.
Bull Sharks and Beyond
The star attraction is the bull shark — the Bat Islands offer the only reliable bull shark diving in Costa Rica, with encounters highly probable from June through October when warmer, nutrient-rich waters draw them in groups. Individuals frequently reach 4 to 5 meters. Beyond the bull sharks, the sites attract Giant Pacific Manta Rays, huge schools of devil rays sometimes numbering in the hundreds, guitar sharks, spotted eagle rays, sea turtles, and dense schools of fish. The volcanic drop-offs and variable currents create the same nutrient-rich conditions that fuel the Catalinas, but in a rawer, more exposed environment.
Advanced Diving in a Protected Marine Reserve
The Bat Islands reward experienced divers with some of the most dramatic underwater scenery on Costa Rica's Pacific coast. Conditions vary with the season — visibility can range from 30 to 100 feet, and currents add the kind of energy that concentrates large pelagic life. The boat ride from Playa Potrero is longer than the Catalinas trip, but the journey is part of the experience. Under The Sea Diving is the only operators in the area running trips here year-round, so you're in good hands from start to finish.
- Depth 30 – 100+ ft
- Visibility 30 – 100 ft
- Water Temperature 76 – 85°F
- Best Season May – Oct
- Diver Level Advanced Open Water and Above
- Current Variable
8 Dive Sites to Explore
The Bat Islands are not a single dive site — they are an island chain with multiple distinct dive sites, each with its own character, depth, and marine life. Under The Sea Diving knows every one of them.
- Gran Susto
- Bajo Negro
- Arcos
- Turtle Point
- Punta Oeste
- Shark Cave
- Virador
- Isla San José
Getting There & What to Expect
Under The Sea Diving departs from Playa Potrero for the Bat Islands year-round — we are the only operators in Guanacaste to offer this consistently. The boat ride is approximately 1.5 hours depending on sea conditions. We run two and three-tank trips and visit multiple sites within the island chain. A minimum of Advanced Open Water certification is required, and we strongly recommend recent logged dives in current-heavy conditions before embarking on this trip. All rental equipment is available from our beachfront dive shop. Because the Bat Islands sit inside Santa Rosa National Park, a park entry fee applies and is included in your trip cost. Book in advance — trips fill quickly during bull shark season.
Ready to Dive the Bat Islands?
Contact our team to book your expedition. We'll make sure you're prepared for some of the most memorable dives of your life.
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