Tuesday, 28 May 2013

Undersea Hunter Group - the Argo

Location: Isla del Coco (Cocos Island), Costa Rica. 

We boarded the Argo in Puntarenas, Costa Rica, and were welcomed by the crew with fresh fruit smoothies, firm handshakes and warm smiles. During lunch we disembarked and started our 36-hour boat ride to Isla del Coco (Cocos Island). It is at Cocos Island that we spent 7 days diving some of the most incredible dive spots the world has to offer. Cocos Island is known for its biodiversity of mega fauna, boasting significant schools of hammerhead sharks, whale sharks, yellow-fin tuna, Galapagos sharks, rays, tiger sharks and enormous schools of fish. 

Cocos Island was formed during a volcanic upheaval about two-and-a-half million years ago and is composed of basaltic rock, labradorite and andesite lava flows. It is located in the Eastern Tropical Pacific, 300 miles southwest of Costa Rica: ~ The Undersea Hunter Group.

The Vessel

The Argo vessel is equipped with everything you could imagine being required for the most luxurious of live-aboard trips. The cabins are comfortable and spacious; each with its own en-suite, two bunk beds & ample storage.

  • Level 1: 6 twin-share cabins.
  • Level 2: Cinema, dining area, kitchen, dive platform, camera storage, dive-gear storage & submersible.
  • Level 3: Lounge room, bridge, bow section, sun deck & 4 twin-share cabins.
  • Level 4: Sun deck complete with a 360 degree view.

For a detailed and interactive deck plan of the Argo click here.


Meal times are structured, with breakfast at 8 am, lunch at 1 pm & dinner at 7 pm. Snacks, including sandwiches/wraps/pastries, are served after every dive. The kitchen is permanently stocked with free beer and other non-alcoholic beverages, such as tea, coffee, juice, iced tea and sodas. The boat has a wine cellar on-board, where you can purchase from a wide selection. You are free to bring snacks and drinks on-board too.

The chef is able to cater for all dietary in-tolerances including gluten. The kitchen goes as far as to provide gluten free: beer, cereals, snacks and desserts.

Typical meals include:

  • Breakfast: omelettes, fresh toast and fresh fruit
  • Lunch: rice, beans, chicken legs/fresh fish and salad.
  • Dinner: burgers/steaks, salad, vegetables, tiramisu  

In the late evening, after dinner, the dive schedule for the next day is provided.

On-Board Extras and Activities 

When aboard the Argo you can expect to complete between 21 & 25 dives over 7 days. You are able to sit any dive out, should you become exhausted. If you do, there are many free on-board activities you can enjoying, including:
  • A surround-sound cinema with a comprehensive movie library
  • Board games
  • Book library 
  • Sun deck for sun-baking
  • Taking photos of Cocos, the horizon or sunrises/sunsets from the Argo
  • Engage freely with the staff, asking as many questions about the island and the ecosystem as you would like, as they are all competent team members with plenty of experience

These activities help to create and strengthen new friendships between passengers, staff and Cocos Island rangers when they are on-board.

A free laundry service is provided on the boat. This means you can travel light and not worry about running out of clothes.

On-board satellite internet is available for $20 per megabyte.

Dive Breakdowns 

It is expected that you bring your dive certification card & dive insurance details with you. All tanks are filled with Nitrox so it is paramount that you are suitably certified. Two tender boats shuttle you from the Argo to each dive site. Most dives begin with negative descents and require a roll back entry. During the dive briefing you will be instructed to meet at 10, 15 or 20 m depth at a particular underwater location. A dive is never cancelled due to weather because the island always has at least one sheltered side. Below is a summary of the dive experiences at each dive sight.

The above is a dive map illustrating the below outlined dive sights and what megafauna was spotted where. 

Dive #1 - Chatam Bay

The Undersea Hunter Group take safety seriously. We performed our first dive in Chatam bay at a max depth of 15 meters, to test our equipment and buoyancy and to become accustomed to the water temperature. Two Cocos Island rangers followed us to ensure that we were not touching any marine life and that we were only settling on exposed rocks and / or sand.

Dive Details:

Maximum Depth: 15.2 (m) / 50 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 29 degrees Celsius
Downtime: 57 minutes


Upon our return to the Argo we were provided with a dive briefing for the next two dives. This was followed by a presentation prepared by the Cocos Island park rangers. The presentation included ranger duties and goals, helpful diving tips, an outline of what to expect when diving at Cocos Island and information regarding on-land tours.

Dive #2 - Manuelita Out

At Manuelita we saw a whale shark, oceanic manta ray, Galapagos shark, yellow-fin tuna, mobula rays and a school of hammerhead sharks. The Undersea Hunter Group compiled the official dive map / sites for the island. This is a testament to the experience and knowledge the crew have about the island and what lives there. Their understanding of currents, times and seasonal variances make them dive-planning experts.

Dive Details:

Maximum Depth: 31.9 (m) / 104 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 28 degrees Celsius
Downtime: 40 minutes

Dive #3 - Manuelita Channel

This was a nice and relaxing dive. We had ample opportunity to practice our photography skills as the current drifted us along.

Dive Details:

Maximum Depth: 22.5 (m) / 73 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 27 degrees Celsius
Downtime: 44 minutes

Dive #4, 11, 16 - Dirty Rock

Dirty rock has a high number of cleaning stations where heaps of marine animals come to get cleaned. This includes the white tips, Galapagos sharks and whale sharks. Immediately below the anchor point/boat at 30 meters is the first of many cleaning stations. Without fail many white tips settled less than a meter away from our group at this station.

Dive Details:

Maximum Depth: 35.0 - 35.6 m / 
Nitrox Enriched Air @ 32%
Water Temperature: 27 - 28 degrees Celsius
Downtime: 47 - 49 minutes

On dive #4, within the first 20 minutes of settling at this cleaning station, we saw over 50 hammerhead sharks come in slow and close. Over the rest of the dive, from Dirty Rock out to the Pinnacle, we saw at least another 50.

On dive #11, immediately after entry we saw a whale shark at about 20 m in depth and it circled back at about 10 m in depth and moved slowly above us. We continued to the west side and spotted a significant number of hammerhead sharks. At the end of the south side we encountered two large eagle rays dancing  for all of us. We continued to sight large yellow-fin tuna, hammerheads and a second whale shark. The second whale shark swam along the whole face of the north wall, providing for fantastic photo opportunities.

Dive #5 - Maria’s Punta 

This dive site is one of the furthest from the Argo anchor point. Travel by tender takes approximately 15 minutes. This was a very relaxing dive which wasn't challenging (demanding).

Dive Details:

Maximum Depth: 33.5 (m) / 109 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 26 degrees Celsius
Downtime: 46 minutes

Dive #6 - Coral Gardens

This is a relaxing open dive with schools of up to 40 white tips, frog fish, marble rays, flounder, moray eels, damsel fish, lobsters and yellow-fin tuna. This dive site is 3 minutes further away than Maria’s Punta. As we transferred out to the dive site we stopped a few times to view numerous waterfalls.

Dive Details:

Maximum Depth: 25.9 (m) / 84 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 27 degrees Celsius
Downtime: 48 minutes

Dive #7, 13, 14, 17 - Bajo Alcyone 

Discovered and named by Jacques Cousteau, this is a fantastic dive site. During periods when there is no current, you can expect to find schools of fish in 10s of thousands. During periods of increased current you can expect to find schools of hammerheads.

As we started dive #7 we observed dolphins playing at the surface. From the moment we entered we could hear the dolphins singing. We descended to the cleaning station at the end of the anchor line and observed huge schools of fish, hammerheads and moray eels making use of the cleaning stations. As we were drifting back to the anchor line a pod of 5 dolphins swam less than 5 m behind us. At the end of the dive, during our deep safety stop, a whale shark swam by the group about 7 m above us,

During dive #13 the swell and current were calm. We observed a green sea turtle being cleaned in the cleaning station near the anchor line. Schools of hammerheads were nearby and circling in and out of the cleaning station. Approximately half way through the dive we looked up and saw two the silhouettes of two manta rays. 

Dive #14 and #17 were particularly awesome as we saw massive schools of hammerheads swimming above us. This was particularly amazing to see because it is for this that Cocos Island is known: this is represented in the logo, its theme and encourages world of mouth.

Dive Details:

Maximum Depth: 30.6 - 36.7 (m) / 100 - 120 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 26 - 28 degrees Celsius
Downtime: 42 - 52 minutes

Dive #8 - Submerged rock

On this dive it is particularly important to do a roll back entry and sink quickly to the bottom. This is because the tender drops you as close to the swim through as possible. Once you reach the bottom a dive guide motions for each diver to take a turn swimming through the submerged rock. This allows for each diver to have a similar experience. Once each diver has swum through, the group spiral around the dive site, gradually getting shallower. On this dive we saw many large schools of fish, moray eels and spider crabs.

Dive Details:

Maximum Depth: 31.2 (m) / 100 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 28 degrees Celsius
Downtime: 50 minutes

Dive #9 - Manuelita

This was a very quite dive relative to all the others. Here we saw white tips, eagle rays, sea urchins and plenty of moral eels. The variety that the island has to offer is continually surprising.

Dive Details:

Maximum Depth: 30.2 (m) / 100 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 29 degrees Celsius
Downtime: 55 minutes

Dive #10 - Manuelita (Night Dive)

The tender boat took us 250 m from the Argo, to the north side of Manuelita. We descended to the ocean floor at about 18 m deep and gathered in closely. At night, schools of white tips and jacks hunt. The white tips feel the vibrations of small fish in and among the coral and attack in a clumsy fashion. The jacks are more precise and efficient in hunting. 

On the safety stop the dive guide motioned for us to turn off our torches so that we might enjoy playing with the phosphorescence. This was exciting and even without the torches you could make out a surprising amount of detail in the ocean floor, and the actions of the divers surrounding you.

Dive Details:

Maximum Depth: 18.1 (m) / 60 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 28 degrees Celsius
Downtime: 48 minutes

Dive #12 - Chatam Bay @ Night

Chatam Bay was more active than Manuelita during the night, probably because there are more, smaller fish for the white tips and jacks to feed on. There were approximately twice as many white tip sharks present, with an estimated 150+. On this dive we also observed large moray eels scampering along the ocean floor.

Dive Details:

Maximum Depth: 11.8 (m) / 38 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 27 degrees Celsius
Downtime: 33 minutes

Dive #15 - Manuelita Out

Numerous hammerheads came in very close to us as they were getting cleaned. The owner of the Undersea Hunter Group and inspirational player in the ocean conservation movement, Avi Klapfer, joined us on the dive. It was really an honor to dive along side him. We started on the south-east end of the island and traveled west against the current. We did this because marine life often travels against the current too. We saw many Galapagos sharks – in fact one extremely large male approached a mobula ray from behind rather inquisitively. The mobula ray darted off just in time. During our safety stop we saw a very large school of hammerheads travelling approximately 20 m below us.

Dive Details:

Maximum Depth: 31.7 (m) / 104 (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 28 degrees Celsius
Downtime: 61 minutes

Dive #18 - Manuelita

This was a nice and casual way for us to end the dive trip. Max depth was less than all the others. The visibility was very average on this dive. At around 3:45 pm the lobsters were emerging and the jacks were starting to feed.

Dive Details:

Maximum Depth: 30.8 (m) / (ft)
Nitrox Enriched Air @ 32%
Water Temperature: 28 degrees Celsius
Downtime: 49 minutes

Overall Rating:

The Undersea Hunter Group is one of the most professional dive companies we have dealt with. Their attention to detail and diver safety are unrivaled. The crew are eager to please and are passionate about the location and company for which they work. This makes it one of the most pleasurable, informative and overall exciting live-aboard experience we have encountered yet.

The vessel is the most luxurious and spacious vessel that dives at Cocos Island. Furthermore, it has an on-board submersible that enables you to further your already intimate experience of Cocos Island by viewing it from a few hundred meters below sea level. This is both exciting and memorable. The review for this experience will be published soon.

The knowledge possessed by those on board enabled us to see and experience what we did. It is not without the decades of experience accumulated by members on board that we could have see everything we set out to seen. The crew are so passionate about the Cocos Island experience that they naturally tell you the history of the island and biology of the life you see.

We asked the passengers on board what characteristic they appreciated the most about the vessel in particular and these were the top three:
  • Space
  • High quality of food
  • Impeccable finish and cleanliness to the vessel
If you are going to take the time to visit Cocos Island and to experience what has been outlined above, you are going to want to do so with the Undersea Hunter Group. They have two vessels available and we strongly suggest that you view their website for more information: http://www.underseahunter.com/

Dive Flag App proudly support them and look forward to diving with them again some time soon. 

Dive Flag App Rating 10 / 10

Thanks guys!

Best regards,

Frank Vorster
Dive Flag App

1 comment:

  1. This is a game changer in diving. I'll make sure to visit this by the end of the year. I'll first try PNG diving then this one. What a year for me!