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Dive Review of Undersea Hunter in
Costa Rica/Cocos Island

Undersea Hunter: "Probably the best overall shark trip I've done (Argo)", Nov, 2018,

by James K Harris, TX, US (Sr. Reviewer Sr. Reviewer 9 reports with 22 Helpful votes). Report 10624 has 6 Helpful votes.

No photos available at this time

Ratings and Overall Comments 1 (worst) - 5 (best):

Accommodations 5 stars Food 4 stars
Service and Attitude 5 stars Environmental Sensitivity 5 stars
Dive Operation 5 stars Shore Diving N/A
Snorkeling N/A
Value for $$ 5 stars
Beginners 3 stars
Advanced 5 stars
Comments This Argo trip was pretty fantastic compared to my July 2015 trip on the Aggressor. I think part of it was the time of year (early Oct. vs. mid July resulting in slightly cooler water), but a big part was the divemasters’ (DM’s) discipline about staging people in the cleaning stations, making it very clear that we were to get on the rocks and stay there because if anyone was swimming around the sharks wouldn’t come. We had very good success at the cleaning stations (and swimming in the blue).

By the end of the trip (20 dives) I estimate I saw over a thousand hammerheads, lots of Galapagos sharks, silver tips, a black tip, a tiger, a couple of minutes with a 20’ whale shark, a few eagle rays and mobula rays, some silkies, and huge huge huge schools of jacks that we swam into. When we’d swim into the blue it wasn’t uncommon to find schools of 50-100 hammerheads and at times they weren’t that far from us – sometimes as close as 20-30’.

The Argo crew is pretty amazing, with a special nod to Juan Manuel the cruise director/divemaster – I’ve never seen a crewmember who could make all the guests and his coworkers laugh so much. We dove with 4 different DMs, one or two on each dive, and sometimes we had a third with a big camera shooting pictures. There’s no trip video for sale but they make all the pictures they shot available on a computer for everyone to copy to a USB drive or memory card, and guests are encouraged to make their photos/videos available as well. The cabins were comfortable – no issues. The skiffs are fiberglass boats with sun canopies but you can still be exposed to the sun going out or coming back since you mostly sit in the same spot on the side of the skiff all the time.

Some odds-and-ends: they can do laundry for you as long as you get it to them before the last dive day; they have hair dryers but you have to ask for one; soap, shampoo, ear plugs were provided; they had boxes of Dramamine in the salon to combat seasickness for those who ran out or didn’t bring anything; since you have to fly in a day early you have to book a hotel and their shuttle picks up at 4 hotels – Hampton Inn Airport where I stayed, Park Inn, Grano de Oro, and Costa Rica Marriott San Jose. My pickup time for the shuttle to Puntarenas was the last pickup at 11am, and I was the first dropoff at 9:30am on the return (had no problem getting into my room even though I arrived so early); the shuttle stopped for a buffet style lunch so first meal on the boat was dinner; they want you to have DAN dive insurance over other companies because their experience is that DAN works better covering accidents at Cocos; since they don’t have online availability on their website I e-mailed them and asked if they had any openings for 3 or 4 dates I was interested in; if you’re not familiar with tipping on liveaboards check into it before you arrive – most of the guests had no idea what to tip and were asking me since this was my 25th liveaboard but I learned tipping customs vary by country so what’s typical for me isn’t necessarily typical for others; remember to bring gloves – you’re going to be grabbing onto the rocks at the cleaning stations and trying to resist current/surge; a few people developed sores on their feet from kicking so much during swims in the blue so bring lycra dive socks if you think you’re prone to that; they don’t allow brightly colored gear that creates a sharp contrast to the sharks – as a result one of the guests who brought white fins couldn’t use them and had to use rental fins that had shorter blades than hers and she hated them…so avoid bright stripes in wetsuits, anything white, but yellow/neon octo hoses are fine; their rental wetsuits looked like they’d been heavily used (no surprise); if you need a rental regulator set let them know in advance if you want a pressure gauge in psi or bar – all their pressure gauges were psi and those used to diving bar didn’t like trying to figure out psi (specifying this in advance was a suggestion from the cruise director to try to get the company to have both available since their guests come from all over the world).

Water temps were 80-82 degrees with the only thermocline being at the corner of Manuelita Garden and it was thick and cold. It was easy enough to ascend a bit to stay just above it since it was the last dive of the day and not a cleaning station dive. I was wearing a 3mm full suit with a long sleeve Lavacore shirt and was comfortable in the water. DMs were wearing 7mm, rental wetsuits were 7mm, I think there were a few 5mm, and even one 8mm. The temperature problem I ran into was on the skiff rides. The first 3 days we had clouds, cold rain (sometimes driving horizontal rain), wind, and flat-to-6’ seas thanks to a tropical storm that was a few hundred miles away. I froze on the longer skiff rides as the wind cut through my suit and chilled me to the bone. It was always a relief to roll into the warm water. By the 4th day we started getting some sun and it was better. But to guard against cooler/non-sunny weather next time during the rainy season I’ll take a 5mm and maybe bring the 3mm for sunny days.

There’s no longer the night dives with the hunting white tips because of the threat of a tiger attack – I probably would have left my GoPro lights at home if I’d known that. The Argo does 3 dives a day including the last day so 21 dives total (more on this below) with dives at 8am, 11am, and 3pm. Meals are usually 7am, 1pm, and 7pm. For dive briefings they have professionally produced placards showing the layout of the dive sites which I found better than the typical hand drawing on a whiteboard – depths and pressure limits were briefed in both feet/meters and psi/bar.

Since the Argo carries the Deep See submersible, it anchors in Chatham Bay (close to where the Deep See dives are made) and never moves to Wafer Bay. This means a couple of things - longer skiff rides to sites on the opposite side of the island (I think our longest ride was 20-25 minutes – remember my chilled to the bone comment above?), and you won’t be able to get a signal from the cell tower unless you go on the island tour. You can throw your phone in a Ziploc bag in the forward covered area of the skiff and on the runs to the other side of the island to sites like Dirty Rock, Dos Amigos, and Punta Maria your phone will pick up the cell tower and can send/receive messages that are queued-up.

Because of the tiger attacks, on most dives there were two DMs with the group, one leading, one trailing. Entry into the water varied based on currents/surge but only once or twice did all 9 of us backroll in at the same time (most were negative entries). More typically the first 4-5 ready would get to roll in and descend with the rest of the group being ready 20-30 seconds later. Sometimes a DM would roll in first to check the current or check if there were cleaning fish at the cleaning stations and then the plan would adjust if necessary. The group stayed loosely together but if divers got too far away the DM would rattle their noisemakers and wave them back to the general area of the group. DMs carry a pole about 3’ long with what looks like a quarter inch lag screw on the end for discouraging tigers that get too close. We had no need for them but the lead DM told me he’s had to use his several times.

On most dives we’d hit a cleaning station and stay as long as there was action. Once it ended (or if it never materialized) we’d swim around either the island/site formations or swim into the blue. We mostly had mild currents although we had some moderate surge at some cleaning stations which definitely required gloves to hold onto the rocks. Some of the cleaning stations are urchin minefields so be careful when you’re getting into a spot. On most dives at 700psi we were to tell the DM low-air and we’d swim out into the blue and at shallower depths to extend times eventually leading to a group safety stop. They had about six steel 100 cu.ft. tanks available for rent for fast breathers (but more air volume brings its own problems). At the cleaning stations we monitored our no-deco time and at 5 minutes to go were to ascend 10-15’ to back off from that time. But once someone rises up the action typically ends so we’d move on to the blue or other parts of the dive in shallower water. Conservative computers like Suuntos can definitely be a problem for the group since they’ll usually reach the no-deco time quite a bit before other brands of computers. My skiff’s dives were 40-69 minutes with an average about 50 minutes.

Surfacing was only allowed at the DM’s sausage and there was to be no swimming to the skiff even if it was 20-30’ away because you become a tiger attraction. On a couple of dives around Manuelita we were sent up to the skiff in groups of 2-3 so not everyone’s thrashing on the surface at once. Hand up cameras and fins and then climb the ladder (it’s a good ladder). Tanks, weights, fins stay on the skiff.

Air fills were 2850-3200psi, nitrox was 31.9% or 32%. They measure the tanks and write the readings in a notebook that you have to sign before each dive. Several people didn’t know how to set their computers for nitrox and didn’t bring manuals so the DMs were struggling to help figure out the settings for them.

Because of bad weather/poor action at some of the distant sites, we did 11 of the dives around Manuelita. Cleaning station #1 was almost always great hammerhead action and we were able to be protected from the weather. We did Punta Maria (Galapagos cleaning station) once with great action, Big Dos Amigos once (not worth the long ride), Dirty Rock 3 times but mostly wasn’t that good, Alcyone twice (1st time only had the whale shark, 2nd time was nothing at the cleaning station but ran into a huge school of snapper and hammerheads in the blue), and a shallow site called Paraja that had no sharks but lots of fish and critters hiding in the rocks. Nobody on my skiff was complaining about doing Manuelita so many times (plus it’s only a 5 minute skiff ride).

The other skiff had three people run out of air, two on the same dive. Given that they had 20 and 30 dives under their belts before the trip it’s not surprising to me the two ran out. Review length limits prevent me from saying more on this but there were at least 2 DM’s on the dive and they were both able to provide octos to them to breathe on. It seemed to me they split the guests between skiffs based on experience, but kept family/friends together if desired.

On the number of dives, doing the island visit or the submersible will cause you to lose dives. Touring the island it will cost an afternoon dive. If you do the 100 meter submersible it will cost the 8am dive the day you do it. If you do the 300m dive in the morning it’ll cost both morning dives since it’s a 3.5 hour trip. If you do it in the afternoon it costs the afternoon dive.

I did the 300m submersible in the afternoon. I treated it as mad-money because how many people do you know that have been down a little over 1000’ in the ocean? Other than the topography, I saw grouper hunting using the sub’s lights, I saw king crab, a few eels, a lot of jellynose fish, but none of the really exotic stuff like translucent fish and other alien-looking fish in the deep dark ocean. From talking with the sub pilots, it sounds like the better show is the 100m trip to the top of a seamount (note – the 300m trip is NOT an extension of the 100m trip – the sub is towed out to a different location in 600’ of water and you descend straight down to that depth just looking at the blue, then you’ll drive around a little bit to find the edge of the wall and then go over it and descend down the wall to a little over 1000’). I think next time I’ll do the 100m trip. The pressure in the submersible is maintained at 1 ATM so it doesn’t affect your nitrogen loading for diving.
Websites Undersea Hunter   

Reporter and Travel

Dive Experience 501-1000 dives
Where else diving Galapagos, Socorro (3x), Palau, Cocos (2x), TX Flower Gardens (15x), Hawaii, Bahamas, Caymans (2x), Belize, Cozumel, Tiger Beach
Closest Airport San Jose - SJD Getting There DFW -> MIA -> SJD going
SJD -> DFW return

Dive Conditions

Weather sunny, windy, rainy, dry Seas calm, choppy, surge
Water Temp 80-82°F / 27-28°C Wetsuit Thickness 3
Water Visibility 75-90 Ft/ 23-27 M

Dive Policy

Dive own profile no
Enforced diving restrictions Stay together as a group
Liveaboard? yes Nitrox Available? yes

What I Saw

Sharks Lots Mantas None
Dolphins None Whale Sharks 1 or 2
Turtles 1 or 2 Whales None
Corals 3 stars Tropical Fish 3 stars
Small Critters 3 stars Large Fish 4 stars
Large Pelagics 5 stars

Underwater Photography 1 (worst) - 5 (best):

Subject Matter 5 stars Boat Facilities 4 stars
Overall rating for UWP's N/A Shore Facilities N/A
UW Photo Comments They have two long shelves where people work on their cameras and where the charging outlets are. Underneath are 18" x 18" x 12" cubby holes for each diver where you store your stuff like smaller cameras, extra batteries, etc. The shelves aren't super long so you can't get more than about 3 people working on each shelf at a time if any are working on big rigs. They have a camera rinse tank as well as a wet suit rinse trash can that are refilled every day.
Was this report helpful to you?
Report currently has 6 Helpful votes

Subscriber's Comments

By Ellen Marie Smith in MN, US at Nov 09, 2018 18:16 EST  
Thank you for your great review - sad that the night dives are no longer happening, but understandable.
By Serguei prigarine in Neuheim, US at Mar 14, 2020 10:55 EST  
Excellen and comprehensive review, thank you!
By Serguei prigarine in Neuheim, US at Mar 14, 2020 10:55 EST  
Excellen and comprehensive review, thank you!
By Serguei prigarine in Neuheim, US at Mar 14, 2020 10:55 EST  
Excellen and comprehensive review, thank you!
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Note: The information here was reported by the author above, but has NOT been reviewed nor edited by Undercurrent prior to posting on our website. Please report any major problems by writing to us and referencing the report number above.

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