Costa Rica

Open Water Diver

Year Round

Hammerheads. Eagle Rays & Whales

UD Rating - 4 Star

Cocos Island Aggressor

Dive into the wild waters of Cocos Island with hammerheads, mantas, and whale sharks .

Escape to Cocos Island for a Costa Rican liveaboard scuba diving adventure! Cocos is a lush, green uninhabited island resting 342 miles off Costa Rica's Pacific coast. Rocky pinnacles surrounding Cocos are beacons for big animals and big action. Schooling hammerheads, countless white-tip sharks, mantas, tuna and even whale sharks call Cocos home.

The Cocos Island Aggressor is a newly built 124-foot yacht designed for comfort, safety, and stability. Powered by diesel engines and cruising at 10 knots, it offers 110-volt power onboard. Accommodations include 11 staterooms for 22 guests—4 master staterooms on the upper deck and 7 deluxe staterooms with twin beds on the lower deck. All rooms feature private bathrooms, individual climate control, and monitors with media players.

The yacht features a spacious salon, large sun deck with chaise lounges and deck chairs, and a stocked beverage cooler. Diving amenities include personal gear lockers, 80 cu ft. tanks, weight belts, and both K-valve and DIN tank compatibility.

Guests can enjoy nightly activities such as marine life presentations, movies, games, and access to a library with books and fish ID guides.

All meals, snacks, and beverages are included.

Master Stateroom

All Master Staterooms have a large picture window, private bathrooms and showers, individual climate control, monitor with media player and hair dryer. Stateroom #10 has a queen bed (Couples only), #'s 8, 9 & 11 have two twins.

  • Air-conditioning
  • Private bathroom & shower
  • Large picture window
  • Monitor w/ media player
  • Hair dryer

Deluxe Stateroom

All Deluxe Staterooms have two single beds, 2 port holes, private bathrooms and showers, individual climate control, monitor with media player and hair dryer.

  • Air-conditioning
  • Private bathroom & shower
  • Port holes
  • Monitor w/ media player
  • Hair dryer

Route Options

Cocos Island National Park was designated a World Heritage site by UNESCO in 1997. Weather permitting, all guests are shuttled ashore to hike through the jungles of Cocos and swim in her many waterfalls. All ten-day trips offer seven days of Costa Rica liveaboard scuba diving.

The Okeanos Aggressor II offers 8, 10 and 12 night itineraries around the Cocos Islands. Divers should be comfortable diving in stronger currents and open water conditions with thermodines. There are 3 dives per day and diving is conducted from large dive tenders. Cocos Island is essentially a huge mountain starting thousands of meters below the surface and sticking out as an impressive island with steep cliffs and little island groups. The extremely wet climate and oceanic character gives Cocos a character that is not shared with either the Galapagos or any of the other islands in this part of the world.

Vessel Details

Length 124 ft.
Beam 28.5 ft.
Cruising Speed 10 knots
Passengers 22
Staterooms 11
Staff 8
Boat Navigation and Safety Radar, GPS, Radio VHF/DSC/SSB, Emergency Rafts, Life Vests, Fire Alarm & Fire Extinguishers, First Aid Kits
Air Compressors 2 x mako K14 and K15 air compressors with cascade storage
Dive Deck Spacious dive deck with rinse tanks and storage lockers
DIN Adaptors Available on board
Tenders for diving Available on board
Complete Set of Rental Gear 10 nights - $260
Scuba Package 10 nights - $225
Regulator 10 nights - $90
BCD 10 nights - $90
Dive Computer 10 nights - $90
Mask/Fins/Snorkel Package 10 nights - $75
Wetsuits 10 nights - $70
Night Dive Light $8 per night
Nitrox Unlimited 10 night charters - $150
Nitrox Student Fills 10 night charters - $130
100 cubic ft and/or 15L Tank Rentals 10 night charters - $120

Available Experiences

ITINERARIES AVAILABLE IN THIS DESTINATION

Marcelina

Saturday, 28 April 2012

Mr Moss and Club on-board the Okeanos Aggressor

Mr Moss and Club went on a liveabord on Costa Rica.

Mr Moss and Club on-board the Okeanos Aggressor

What Our Customers Have To Say

Reviews from our Clients, Journalists, Photo Pro's and our own Experts

Our reviews and blogs are an additional guide to evaluate of the holiday is exactley what you are looking for or not. Some love an Eco-Resort, some love air-con and a flat screen TV, we aim to ensure you get what you are looking for, at great value for money.

10 days on board the Okeanos Aggressor

If you’re looking for a tour operator who is efficient, knowledgeable and super organised, Marcelina , Ultimate Diving is the place to go! Pre-trip, nothing was too much trouble, and the trip itself? Amazing. Every little detail was taken care of, and of course, the diving was incredible.

Amy S

Okeanos Aggressor followed by Arenal Volcano & Monteverde Cloud Forest Tour

Please find enclosed a small token of our appreciation for the organisation of the trip to Cocos Island. The whole trip went without a hitch. Every bus appeared on time, every hotel was expecting us, clean and comfortable and all the guides were knowledgeable and friendly. Without exception though, was Okeanos Aggressor. The boat, crew, food and accommodation were first class and to be recommended to everyone and anyone. The diving lived to up expectations (although the crew reckoned it was only average, so another trip could be on the cards). The weather was also exceptional as we had calm conditions all time and very little rain. I could go on and on but just want to thank you once more for an exceptionally well organised trip and would (will) certainly recommend Ultimate Diving to all.

Mr Moss and Club

7 nights on-board the Okeanos Aggressor

We had a really good time, the crew on the boat were fantastic, the food was amazing and the diving was superb, a lucky combination of all on a liveaboard. On our check dive we had mantas, schools of hammerheads and dolphins. Other sightings included tiger and Galapagos sharks, a phenomenal experience! After the first dive and seeing so many sharks, we thought it was quite nice and almost took them for granted. The diving here was spectacular. The boat was not glamorous but very clean and comfortable. The cabins were of reasonable size with a double and a single bunk allowing for extra storage space. Towels were changed every couple of days and after dives you get a guide waiting for you with a nice hot towel and great snacks.

Mr & Mrs Underwood

Bajo Alcyone

Cocos Island, Costa Rica

Bajo Alcyone is the place to see the Hammerheads amongst other pelagic. The abundancy of resident sea life makes this site one of the island’s signature dives. Mantas, Whitetip Sharks, Whale Sharks, Silky, Blacktip Sharks, and hundreds of schooling Hammerheads are everywhere. And underwater plateau, discovered by Cousteau when he visited Cocos Island, is home to a variety of sharks.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 25m

Dirty Rock

Cocos Island, Costa Rica

Located near Wafer Bay, Dirty Rock is an impressive and exciting dive. Noted as one of our guests’ favourites, here you will come up close and personal with Whale Sharks that often cruise around this site.

Dirty Rock is perhaps best known for the hundreds of Marble Rays and huge schools of Jacks that can be seen here. A swim through one of the schools is definitely worth the trip!

  • Dive Type: Boat Dive
  • Diver Level: Advanced Open Water Diver
  • Max Depth: 39m

Big Dos Amigos

Cocos Island, Costa Rica

Dos Amigos Grande is better known for its huge arch, a swim through so big that an entire diving group can move through it at the same time, Marble Rays swimming among divers, Eagle Rays feeding or mating, and schooling Hammerheads are typical scenarios at this memorable dive site.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 18m

Lone Stone

Cocos Island, Costa Rica

There are some nice shark photo opportunities throughout the dive, and a very cooperative marbled stingray. Slowly swimming through the huge rocks, guests will noticed a vertical crack in the reef, about 25-30 high and perhaps five feet wide. With shimmering sunlight streaming down from fissures in the top, you could see the fish, hiding from the current, and the ever-present predators. There are silver Snappers, Yellow Grunt, Red Cardinal Fish, and big Trumpet fish in one vertical school.

  • Dive Type: Boat Dive
  • Diver Level: Advanced Open Water Diver
  • Max Depth: 30m

Submerged Rock

Cocos Island, Costa Rica

Underwater, this rock plunges down both sharply and gradually. It is broken up with large ledges, some with sandy bottoms, and an outer pinnacle. The colourful, prolific fish life gives relief to the harsh contours of the reef. Sometimes the fish gather in such numbers that they momentarily blot out the sun.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 18m

Lobster Rock

Cocos Island, Costa Rica

On this finger-like rock, divers can easily approach large white tips lying on the bottom in great numbers. In the deep sandy area surrounding it, the elusive rosy-lipped batfish can be found between 90 and 120 feet.

Marine Life: White tips, marble rays, manta rays, eagle rays, red lip batfish, frogfish, garden eels

  • Dive Type: Boat Dive
  • Diver Level: Advanced Open Water Diver
  • Max Depth: 33m

Manuelita

Cocos Island, Costa Rica

Manuelita dive site has a boulder formation where you will find hammerhead sharks along with other marine life including lots of White Tips, Marble Rays and schools of Creoles. A great day and night dive. Known as the dive site that never sleeps!

  • Dive Type: Deep Dive
  • Diver Level: Open Water Diver
  • Max Depth: 30

Ubing Rock, Wafer Bay

Cocos Island, Costa Rica

Located at Wafer Bay, the southeast slope of Ubing Rock attracts schooling Hammerheads. This rock drops to a sandy bottom. The rock begins at 20m and falls all the way to 110m.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 30m

Bird Island, Chatham Bay

Cocos Island, Costa Rica

Dove from Chatham Bay, southeast of Manuelita, this site provides a variety of marine life including Frog Fish, lobsters, morays, rays, White Tip Sharks and Hammerheads. There is even a cleaning station.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 30M

Manta Corner

Cocos Island, Costa Rica

South of Cocos Island. The reef is about 27 metres deep if you want to full presence of manta rays! The reef is believed to be part of the submerged mountain range. It can be a boat, drift or deep dive.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 33m

Little Dos Amigos

Cocos Island, Costa Rica

Known for being a hammerhead cleaning station. Located south-east of Cocos Island, below Big Dos Amigos dive site. The visibility is 20m. This dive site often suprises divers as the open sea current first reaches the island at this point bringing in a wide variety of marine life.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 30m

Cabo Atevida

Cocos Island, Costa Rica

Remote from other dive sites on the east side of the island but also attracted by hammerheads like most Cocos dive sites. The marine life has high density and has a wide variety living or passing here.

  • Dive Type: Boat Dive
  • Diver Level: Open Water Diver
  • Max Depth: 30m
Dates Duration Route Room Type Price
23 Aug 2025
2 Sep 2025
10 Nights Cocos Island Adventure Deluxe Stateroom £5399
4 Oct 2025
14 Oct 2025
10 Nights Cocos Island Adventure Deluxe Stateroom £5399
15 Nov 2025
25 Nov 2025
10 Nights Cocos Island Adventure Deluxe Stateroom £5679
13 Dec 2025
23 Dec 2025
10 Nights Cocos Island Adventure Deluxe Stateroom £5399
27 Dec 2025
6 Jan 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5399
28 Mar 2026
7 Apr 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
25 Apr 2026
5 May 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
20 Jun 2026
30 Jun 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
18 Jul 2026
28 Jul 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
1 Aug 2026
11 Aug 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
15 Aug 2026
25 Aug 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
5 Dec 2026
15 Dec 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
19 Dec 2026
29 Dec 2026
10 Nights Cocos Island Adventure Deluxe Stateroom £5479
2 Jan 2027
12 Jan 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
16 Jan 2027
26 Jan 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
30 Jan 2027
9 Feb 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
13 Feb 2027
23 Feb 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
27 Feb 2027
9 Mar 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
13 Mar 2027
23 Mar 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
27 Mar 2027
6 Apr 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
10 Apr 2027
20 Apr 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
24 Apr 2027
4 May 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
8 May 2027
18 May 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
14 Aug 2027
24 Aug 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
28 Aug 2027
7 Sep 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
24 Sep 2027
6 Oct 2027
12 Nights Cocos Island Adventure Deluxe Stateroom £6639
4 Dec 2027
14 Dec 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599
18 Dec 2027
28 Dec 2027
10 Nights Cocos Island Adventure Deluxe Stateroom £5599