Bat Islands · Costa Rica · Pelagic & blue water
Big Scare
Giant Pacific mantas turn up on the bull shark dive
Big Scare sits just off the tip of the last island in the Bat Islands chain, and it is the site bull sharks made the archipelago famous for. Profiles often reach 30 m, current can arrive at any point in the dive and is strong and unpredictable at depth, and visibility swings between 5 and 27 m. The site lies inside a marine reserve off Santa Rosa National Park, where fish and marine animals are protected from fishing.
Where it is and how deep
10.8729° N, 85.8929° WApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
The crossing takes 45 to 50 minutes on the fast boat from Playa Flamingo, and the briefing ends with an instruction most divers are not used to: make a negative descent. Surge is common here, and dropping in quickly gets the group off the surface and down together rather than strung out on the way. The site sits just off the tip of the last island in the chain, and profiles often reach 30 m.
Bull sharks are what the site is known for, and the same dive produces huge schools of jacks, other fish, eels and rays, with a giant Pacific manta a fairly common visitor. Current is the variable that shapes everything: it can come on at different points in the dive and at depth it is strong and hard to predict, which is why briefings ask for a tight group and why the guide is likely to call the turn early rather than late.
Marine life and season
- Bull sharks
- Manta rays
- Trevally & jacks
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Fair | Fair | Fair | Fair | Good | Good | Prime | Prime | Good | Good | Fair | Fair |
Season follows Bat Islands: Bull sharks are most reliable May-Oct, peaking Jul-Aug; Dec-Apr's cooler Papagayo upwelling brings clearer but colder water and far fewer sightings.
Know before you go
- Current can come on at any point in the dive and is strong and unpredictable at depth; stay with the group and expect the guide to end the dive early.
- Surge at the site makes a slow descent awkward, which is why briefings call for a fast negative entry rather than a line descent.
Dive videos
The Big Scare Bat Island Costa Rica · Victoremanuel1965 on YouTube
Whale Shark at Big Scare, November, Guanacaste, Costa Rica · James Wire MD Photography on YouTube
Questions divers ask
How deep is the dive at Big Scare?+
Profiles often reach 30 m, and the dive is planned around that depth rather than a shallow reef top. Combined with current that is strong and unpredictable down there, it is why operators ask for an advanced certification.
When are bull sharks most likely at the Bat Islands?+
Bull sharks are found year round at the Bat Islands, but most trips and most sightings fall between mid-May and early November, which is the stretch operators build their schedules around.
Sources
- Diving the Bat Islands — Rocket Frog Divers
- Rich Coast Diving - Costa Rica — Rich Coast Diving
In The Logbook
- Where to dive with tiger, bull and white sharksBig animals · 14 min read
- Where to dive with manta rays, month by monthBig animals · 8 min read
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