Cocos Island · Liveaboard
Aggressor Adventures
Cocos Island dive liveaboards from Puntarenas
Aggressor Adventures, once called the Aggressor Fleet, runs 2 dive liveaboards to Cocos Island National Park, about 36 hours offshore from Puntarenas. Trips last 8, 10 or 12 nights, with all dives made from tenders around the island's seamounts and pinnacles. It suits experienced divers who want hammerheads, white-tips and big pelagics.
What they offer
Aggressor Adventures, the company once known as the Aggressor Fleet, is one of the oldest names in liveaboard diving. In Costa Rica it runs trips to Cocos Island National Park, a remote, forested island in the open Pacific about 36 hours by boat from the mainland. Cocos is a UNESCO World Heritage site and one of the best-known shark dives anywhere, famous for schooling hammerheads.
Two yachts work this route, and both leave from Puntarenas on the Gulf of Nicoya. You board, the yacht leaves straight away, and the long crossing begins. Once at the island, all diving is done from tenders, and each yacht carries 2 of them.
The yachts
- Okeanos Aggressor II: 120 feet long with a 27-foot beam, for 22 guests in en-suite staterooms.
- Cocos Island Aggressor: a newer yacht, built in 2022, 124 feet long with a 28.5-foot beam, also for 22 guests in 11 staterooms. Its first trip was in January 2023.
Both are full-service dive boats with meals, crew and dive guides included in the trip. Ask about nitrox when you book.
The trips
Trips run 8, 10 or 12 nights. Because the crossing eats up about 3 days of the round trip, the longer trips give you more time in the water. Aggressor's average figures are about 15 dives on an 8-night trip, 21 on a 10-night trip and 27 on a 12-night trip.
Typical dives are in the 55 to 110 foot range, and water temperatures run about 72 to 82 F, with colder thermoclines at depth. A 3 to 5 mm wetsuit is the usual advice. Night diving isn't currently offered. Marine life includes schooling hammerheads, white-tip reef sharks, mantas, tuna and, with luck, whale sharks. With permission from park rangers, guests can sometimes go ashore to walk the island's trails and see its waterfalls.
Where you leave from
Both yachts sail from Puntarenas. Boarding and departure times depend on the tide, so you'll get exact times closer to the date. Most guests fly into San José and transfer by road to Puntarenas, about 1.5 to 2 hours away, so plan to arrive in Costa Rica at least a day before departure.
Who it suits
- Experienced divers. Cocos has currents, depth and open-ocean conditions. Most operators expect advanced certification and recent dive experience.
- Shark and big-animal enthusiasts.
- People who are fine with a long sea crossing. It's about 36 hours each way across open ocean, so bring seasickness remedies if you need them.
Good to know before you book
- Spaces are limited to 22 guests per yacht, so book early. Dive travel agents already list departures for late 2026 and 2027.
- Ask what is and isn't included in the trip, such as park fees, nitrox and transfers.
- Dive insurance is strongly recommended because the island is far from any hyperbaric chamber.
Frequently asked questions
How long does it take to get to Cocos Island?
About 36 hours by yacht from Puntarenas, each way.
Can I fly to Cocos Island?
No. There's no airport. Liveaboard yachts are the only practical way to visit and dive there.
Which yacht should I choose?
Both carry 22 guests and run similar trips. The Cocos Island Aggressor is the newer of the two, built in 2022.
Is there night diving at Cocos?
Not currently, according to Aggressor's Cocos page.
What will I see?
Schooling hammerheads, white-tip reef sharks, mantas, tuna and sometimes whale sharks, though sightings always vary.
