After a winning bid in a Sea Save auction for a 13 day liveaboard trip to Cocos Island, Costa Rica. I became very excited that I will finally get the opportunity to see schooling scalloped hammerhead sharks in the wild. As I have never seen a hammerhead anywhere in my 15 years of diving. You just don't see scalloped hammerheads in Australia not even on the Great Barrier Reef or the Coral Sea as they are listed on the IUCN red list of threatened species as endangered and are very rare.
Picture Gallery - Cocos Island, Costa Rica 8-20 September 2011
The trip was organised by the Sea Save Foundation aboard "Sea Hunter" from the Undersea Hunter Group and hosted by Georgienne Bradley and Jay Ireland, both professional photographer and videographers. Jay and Georgienne have fought to protect Cocos Island for over 20 years. They are currently working with the local park guards to develop better communication and create more transparency between the remote park guards and the rest of the world.
Cocos Island is dive central for divers looking for shark action, pelagics and high adrenaline diving. And one of the few places in the world where scalloped hammerheads can be found in large numbers. Cocos Island is in the Pacific Ocean 560km (340 miles) off the Coast of Costa Rica and receives about 275" of rain every year, resulting in verdant, lush tropical rain forest and spectacular waterfalls that cascade down vertical cliffs hundreds of feet high, this means its often raining and it was. The crossing from Puntarenas took us 32 hours, meaning a full day at sea to and from the island. I enjoyed 9 full days of diving with 3 dives per day plus a night dive, all dives on nitrox 32.
The Diving at Cocos Island
Once we reached Cocos Island and anchored it was late afternoon, it was overcast and raining. Looking at the island for the first time I admired how lush and green it looked with cascading waterfalls and lush rainforest, which suggests that it is generally overcast and raining here. We did have our fair share of soakings on the way to and from the dives sites but we also had sunny weather as well as the rain storms generally don't last long.
After dinner we met the park rangers who explained about the island, its marine environment, what we can and can't do. They also explained their function and problems they face with poaching from fishing vessels, they do an excellent job and they were very welcoming.
After a good night sleep breakfast was served at 06:00 a.m., followed by our introductory dive briefing by Wilson who has been with the Undersea Hunter Group a long time. He is a very funny man and cracked us up, but the dive briefing was also very informative. The Sea Hunter has two diving tenders each catering for 10 divers so we were split into 2 groups. Wilson was the divemaster on my group and Federico the other, they would both rotate during the trip, the 2 tenders go to different locations.
Manuelita Coral Garden (Manuelita inside)
This was the first site I dived at Cocos and is an easy and excellent dive, sloping down gently from Manuelita a rocky coral reef from about 3-16m with a sandy bottom in about 16-20m of water.
Within a minute or so of reaching the bottom a 2.5 metre Galapagos shark swam by, numerous whitetip sharks either rested on the bottom or glided over the reef. A pair of scalloped hammerheads soon approached but turned away, we were to see another one approach before the end of the dive.
We dived this site several times during the trip with more sightings of scalloped hammerheads, whitetip reef sharks, loads of spotted eagle rays, marble rays, large moray eels, black frog fish, also another couple of orange frogfish. This was also the site for the night dive later in the trip. Also sighted a pod of Orca's here swimming past on the surface just before we entered the water, didn't see them below the surface though as they had moved on.
The object of this dive is to descend to a cleaning station at about 20 metres to observe hammerheads and anything else cruising past. Then move into the current on the ocean side and ride it around the front of Manuelita (Coral garden side). This was the 2nd dive of the trip and descending down to the cleaning station I didn't observe any hammerheads, some reported a few in the distance. But we did see a trio of spotted eagle rays gliding past and several marble rays.
We dived this site again towards the end of the trip (dive 19) and we did encounter several hammerheads at the cleaning station which remained with us for several minutes. The weather being a lot rougher and moving into the current carried us quite swiftly around the rock, passing another group of divers from the Agressor. After reaching our NDL we set off into the blue where an enormous school of jacks (trevally) surrounded us and a large school of hammerheads passed beneath us. Popping up in groups of two we then waited for pick up by the dive tender.
The dive is between Manuelita and the main island and depending on the direction of the current you either enter inside or outside Manuelita. This being the 3rd and last dive of the day we entered on the inside (coral garden side).
Desending to about 18 metres and waiting for the group to gather we saw a large hammerhead which entertained us for a while. Moving into the channel and descending to about 30-35 metres through the channel there were several hammerheads. I got myself separated as I was exploring a couple of swim throughs and moving over a rocky outcrop on the bottom of the channel I was surpised by a large 4m galapagos shark which came at me and past within inches, got a picture as he was approaching and it filled the frame of my picture as I didn't have a wide angle lens fitted. Catching up with the group we ascended as we approached the outside as we ran out of NDL time, observing serveral whitetip reef sharks before surfacing after our safety stop.
We didn't dive the channel again until the second last day of the trip in the afternoon just before the night dive. This time entering from the outside and descending to the cleaning station at about 20 metres. With the rock to our left we swam into the channel and kept to a depth of 20 metres for the dive. Observed a few hammerheads and several spotted eagle rays towards the middle of the channel. Ending the dive at the coral gardens we saw whitetip reef sharks, marble rays, schools of snapper, goatfish and I saw two orange coloured frogfish which I took pictures of.
This was the first dive of day 2 of diving and the weather was rough we copped a drenching on the boat ride out, observing several waterfalls coming off of Cocos in full flow. Dirty Rock is a rock pinnacle rising just above the waves, volcanic boulders beneath the surface and separated by a sheltered 100m channel. This site was a very popular site with all the divers because of the volume of hammerhead sharks and the incredible bio-mass of fish that congregate here, we dived here another 3 times during the trip.
The site is made up of a number of larger boulders with 3 cleaning stations (16, 24, 30m) to observe the hammerheads. The first one descending down to below 30 metres, I got 39 metres as my dive computer started beeping at me because of my nitrox 32 mix. So I ascended to 35 metres to watch the hammerheads below the bottom cleaning station. We passed by the other two cleaning stations on our ascent and saw loads of scalloped hammerheads, galapogas sharks and whitetip. You had to get some depth to see the hammerheads at first because of a thermocline fuzzying up the water between 30-32 metres 24-25°C above and 18°C below. I was starting to get a little chilly in my 2mil shorty and 1mil radiator shirt. In coming days there would be scores of hammerheads at the cleaning stations.
Diving at Cocos Island, September 2011 video by Des Kerrigan (Bluegroper)
This was the 5th dive of the trip where we descended down the line to a sea mount rising to 30 metres from a sandy bottom. There are two pinnacles to the north rising to 22 and 25 metres which we would get to dive later in the week. On the sea mount there is a crack in the rock and a ledge forming a trench in between. Marble rays glided effortlessly past us as we took our places on the ledge. Large Galapagos sharks swam past and on occasion hammerheads as well. From the ledge watching the action there were also marble rays and a couple of turtles swimming past and I could see several spotted morays amongst the rocks. Eventually we headed out into the blue for our safety stop before surfacing and picked up by the tender.
Returning to this site on dive 13 we descended to the rock and spent a few minutes at a cleaning station before swimming north to the two pinnacles. Here there were many hammerheads cruising past. Wilson descended down below the thermocline below 35 metres and some of the divers followed. I stayed where I was because I wanted to conserve as much air as possible to watch the show the hammerheads and galapagos sharks were putting on. Later I was told that Wilson and the divers who descended below the thermocline found the motherload of hammerheads. But I enjoyed the dive from where I was swimming around the 2 pinnacles as I also sighted many hammerheads, whitetips and galapagos sharks. We were to dive this site again on dive 17 returning to the two pinnacles.
This is an excellent but deep dive and for the experienced as the swim between the rock and the pinnacles is not easy to navigate with poor visibility and current in between, made easy by following Wilson.
This was the 7th dive of the trip and is my favourite site and popular with the other divers requesting to return to this site 3 more times during the trip. This time we would be led by Frederico as he swapped groups with Wilson. The protocol for this dive was the same for Punta Maria; grabbing a line to the mooring before doing a backward roll one at a time so you are not swept away in the current, and descending the line to the underwater sea mount at 30 metres.
Immediately after dropping below the surface you could see the unmistakable shapes of hammerheads, reaching the bottom we were graced with the presence of several large scalloped hammerhead sharks at the cleaning station. As we swam around the rock to several places schools of scalloped hammerheads would swim overhead, huge baitball like schools of fish were about with the hammerheads getting quite close at times. Marble rays, leather bass and whitetip sharks assembled on the bottom, moray eels hide in cracks and crevices as the hammerheads lean to one side as they were being cleaned by the king angelfish. Returning to the mooring and starting our ascent Federico signalled us to drift with him into the blue to do our 5 minute safety stop where we saw more hammerheads swimming about. This was a very enjoyable dive right before breakfast and one we would repeat 3 more times during the trip with each dive being just as amazing as the first.
Being the 8th dive of the trip and diving it at low tide the rock just breaks the surface with a lot of white water swirling about. We approached with caution and the tender dropped us off and we quickly descended to 18 metres to escape the surge waiting for everyone before exploring the perimeter of the rock.
Several whitetip sharks were patrolling the perimeter of the rock as we made our way around to an arch that cuts right through the rock. Schools of blue and gold snappers, bluefin trevallys, and numerous jacks occupy the opening. We took it in turns to swim through the arch but there was quite a lot of surge and it was tough swimming through it as it pushed and pulled you. Once through, swimming to the left there were more whitetip reef sharks and we swam back around the rock to the start of the arch. Before swimming well away from the rock to do our safety stop and so the tender could pick us up.
This is the island between Manuelita and Viking Rock a nesting site for red-footed boobies. The 9th dive of the trip after a short boat ride to the far side of Isla Pajara we descended to the bottom in about 30m of water while several hammerheads swam back and forth just above a sandy bottom. From here we did a drift around the island to the other side in a mild current into a reef of hard corals. Where there were numerous guineafowl puffer fish and spotted boxfish, several enormous moray eels were discovered hiding in the crevices. And the obligatory whitetip reef sharks either rest on the bottom or swimming casually about the reef.
The 15th dive of the trip and a short boat ride led us to Viking Rock a small helmet shaped island on the north west corner of Wafer Bay. After descending to 30 metres we saw 3 hammerheads, several marble rays and a few whitetip reef sharks as we drifted around the rock, little else of interest compared to other sites we had dived.
Small Dos Amigos
Dos Amigos Pequeno is the southernmost part of the island, not always accessible during the rainy season due to the rough surge around this exposed site. This was dive 16 of the trip and we hadn't dived it until now because of weather and ocean swells and it is quite some distance for the tender to travel. This was another whitewater entry once the tender approached the rock we all did a backward roll and quickly descended down to 18 metres to escape the surge from the surface, the bottom is at 37 metres. Soon after our descent we found a cleaning station where we observed 3 large hammerheads before continuing around the rock at a depth of about 32 metres of water. We could often see hammerheads in the distance but not coming close enough to get a picture. Once around the otherside of the rock a large school of hammerheads circled and we could get some good pictures. Marble rays and the obligatory whitetip reef sharks were also in abundance during the dive.
The ascent is the same as other sites like this where there is surge and that is to swim well away from the rock into the blue to do our 5 minute safety stop + what ever deco liability we had. Because the diving is so deep here often below 30 metres sometimes I would go over my NDL by a few minutes, but a slow ascent drifting in the blue and always doing a 5 minute stop at 5 metres was enough to satisfy our deco obligations. By the time we surfaced it was raining heavily which made for an uncomfortable boat ride back to the ship. Driving rain like thousands of needles hitting my face as the tender drove back at speed. My sunglasses were not doing it for me so it was better to use my mask.
At Cocos Island when it rains it really rains and I should be used to this as its not uncommon in Sydney to get torrential downpours in the summer or in Cairns. There are numerous cuts in the tropical foliage created by the many waterfalls on the island, all of these waterfalls start running again and present an awesome spectacle as the white water cascades down hundreds of feet to the sea.
Manuelita Coral Gardens at night
Each boat is allowed to run two night dives per trip one for each of the tenders so each diver would get 1 night dive. And tonight was our tenders turn to experience the spectacle of a whitetip reef shark feeding frenzie. The whitetip reef sharks are very common around Cocos Island and are usually docile during the day. But at night here at the Coral Gardens they have learned to swarm around divers lights in a frenzy in search of food. This is why night diving is limited at Cocos Island to just 2 per ship and only 1 per diver, this is so not to interfere too much with the sharks normal hunting and feeding behaviour.
After descending we grouped together and concentrated our lights on the same rock or part of the reef as we cruised around watching the sharks swarm and hunt for prey assisted by our lights. It was an awesome spectacle but we had to keep moving so not to spend too long with lights shining on anyone particular spot. After the dive it was Mardi Gra time with the crew preparing a barbeque for us on the top deck, complete with entertainment.