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Dive Review of Okeanos Aggressor in
Costa Rica/Coco Island]

Okeanos Aggressor: "Some good, some bad", Jul, 2015,

by James K Harris, TX, US (Sr. Reviewer Sr. Reviewer 9 reports with 22 Helpful votes). Report 8330 has 2 Helpful votes.

No photos available at this time

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

Accommodations 4 stars Food 4 stars
Service and Attitude 5 stars Environmental Sensitivity N/A
Dive Operation 4 stars Shore Diving N/A
Snorkeling N/A
Value for $$ 4 stars
Beginners 1 stars
Advanced 4 stars
Comments Water temp was warmer than expected - 85 on most dives, a few dives had a thermocline deep (80-100') that dropped the temp to 80. Most everyone was diving a 3mm full suit.

The group of 21 divers was split between two pangas with each typically going to different sites and then they'd swap so that everyone got to the same sites. At one site a couple of times both pangas went but separated by 30 minutes which worked fine.

My group was horribly unlucky compared to the other group - they had much closer encounters with hammerheads, saw a tiger shark multiple time, allegedly saw a baby humpback. My group had a couple of divers who wouldn't hang on the rocks at the cleaning station or would chase after sharks when they'd show up and I think that went a long way towards the sharks keeping their distance from my group. There were some confrontations with one couple who would do that and the captain and cruise director talked to them but it didn't seem to help.

Panga rides were 5-15 minutes, all gear is kept on the pangas and you'd gear up once you got to the site. You'd backroll in negatively buoyant and head for the bottom to wait on the rest of the group. I often was the first one in and it would typically take 10-15 minutes for the rest of the group to get in and get to depth. I started hanging out shallower because I'd run low on air if I went to 80-100' waiting for the group. The divemaster was last in and then you'd typically hang out deep at a cleaning station waiting for something to arrive. If after 5-10 minutes nothing showed up we'd start swimming around the site and quite often would then swim out into the blue around 50-60' and see what we'd run across. The panga followed but they typically wanted the divemaster to be first on the panga to help people back on board with the panga driver and he typically would surface around 55 minutes.

The longer panga rides were a beating if you were sitting near the front. Choppy seas and the throttle being wide open is going to result in some hard slaps against the water in spite of the best intentions of the driver to recognize the waves and chop the throttle to avoid that.

With the longer panga rides, it taking 20 minutes to get everyone geared up and to the bottom, then taking another 15 minutes to get everyone out of the water, then the panga run back to the Okeanos, sometimes you'd only have an hour before it was time to start getting your wetsuit on for the next dive.

Dives were typically at 8am, 11am, 3pm, and on nights with night dives they were at 6pm. We got 3 night dives so a total of 24 dives for a 10 day trip (7 dive days).

Lasting 55 minutes wasn't much of a problem because the swim in the blue for 20+ minutes allowed for heavier breathers to go shallow and those with more air to stay deeper. On the blue swims is where my group saw most of our hammerheads (typically around 80' although sometimes we'd see small schools overhead so you could get that typical Coco Island shot of hammerhead silhouettes against the sun).

There was more surge than current on most dives and sometimes it was really strong. We had two people get pushed into sea urchins (one hand, one knee), and one diver was slammed into the rocks and it caused his octo to start free-flowing and he couldn't get it to stop for a long time. I think he was down to 100psi at 90' so he used his wife's octo to get up, do a safety stop, and surface. One a few dives the current was uncomfortable to swim against, and our last dive of the trip had an uncomfortable current for most of the dive but as we turned the corner from Manualita Deep the current was the strongest I've been in. It was all I could do to kick to grab some rocks and hang on. I'd guess it was 4-5 knot current. We ended up just letting go and swam back around the side where there was less current.

It's definitely advanced diving and being in good shape will help a lot.

We saw lots of hammerheads (at distance), the largest school was about 50. We saw a 40' whale shark that wasn't in a hurry to leave and I was in perfect position when it appeared out of the blue coming right at me. We saw several tuna, most about 4' long but one was 6' (two of them swam through our group). My group saw a decent sized tiger shark for about 10 seconds on the first dive of our last day (the other group saw a tiger every day). We saw 4 large Galapagos sharks including a large one that came through on a night dive. The other group had a tiger come through on the night dive and it made a move towards the divemaster who was filming it. Lots of marble rays, a few spotted eagle rays, of course lots of white tips, eels were everywhere.

It sounds like 2 night dives is normal but we got 3. Where you dive is up to the park rangers that are out there and a boat on its last day gets priority choice of sites. One of the Undersea Hunter boats bumped us from our agreed-to dive sites on its last day so we ended up going to Alcyon twice in a row(it's not a bad dive but it's the longest panga ride and we ended up diving it 5 times during the week).

Whatever you do, don't miss the night dives. The white tips and blackjacks hunting is pretty amazing to watch. The dive briefings says to stay 8' above a feeding frenzy but you're bigger than all the white tips so I was able to get in very close and they just ignored me. While filming a frenzy in front of me while kneeling on the bottom a feeding frenzy started behind me around my legs. I felt I was getting bumped bump at night, masks limiting peripheral vision, and a frenzy going on in front of me, I just ignored getting bumped. For those divers without cameras they almost didn't need lights during the dive. The divemaster has huge lights on his camera and there were two of us in my group that had GoPros with powerful twin video lights so when you form as a group that's a lot of light so everyone can easily see. You roll in at dusk and there's enough light remaining so you don't need a light while waiting for everyone to get in. But they do require everyone to have a light and a backup light per buddy team but they can be small lights and will work fine (no need to take a big 8 C-cell light).

Take a good pair of gloves because you're going to be hanging on barnacle encrusted rock a lot in current/surge. I had some gloves that I'd been using for a few years and ended up with a 1" circular hole on one thumb tip.

The cabins were smaller than they look in the pictures but there's lots of storage under the lower bunk and in a cabinet built into the wall. Storage around the sink is limited, the sink mirror is against the hull so you can't get close to the mirror if you're needing a close look at something. The light over the mirror is pretty weak as well. The a/c worked well as did the thermostats. Bath towels won't dry in your cabin and they only change the towels out a couple of times during the trip. There's plenty of dive towels available.

The back of the dive deck smelled of diesel for the first few days but there's not much reason to hang out back there since the crane for the panga takes up a lot of space. There was ample room in the covered area where the dive lockers were so that space wasn't cramped.

Due to the depths, nitrox is strongly encouraged (we had 4 air breathers on our trip on the other panga - I don't know what their profile looked like or if they were skipping dives to stay away from the no deco limits. Nitrox for 7 days of diving is $150 + about 13% tax (that 13% tax is on the trip video and stuff bought in the boutique as well). Since the tanks remain on the pangas, after being filled the skiff driver would call your name, you'd go over and watch as he analyzed your tank and then he'd show you the meter so you could then fill out the log. My first tank was 27% (checkout dive) but the rest were 30-32%).

Lots of food and it was pretty good. Normal breakfast items plus made-to-order eggs/omelets every morning. Some folks made comments that the dinner main course was often more done than they liked or was dry but in my opinion still easily edible. If you like soups you'll like the meals on this trip.

The crew was outstanding. Warren the cruise director did a great job and was very friendly. He was one of the divemasters, and the captain was the other (also very friendly). They swapped pangas every day so you get to dive with both. Warren shoots most of the video for the trip DVD, the captain shoots stills that are given away for free.

This was my 5th Aggressor but the first time I'd heard of their "Iron Diver" certificate for those who made all the dives. Kind of a cool thing except they gave them to everyone even if they didn't make all the dives. That stinks of not wanting to make anyone feel bad so everyone gets a "participation trophy".

We had 3 opportunities to go onto the island. The bugs weren't too bad, it wasn't muddy, so I went twice. One time I hiked up to the ranger station at Chatham Bay (about 500' above sea level) and you get some nice views. The crew and some of the guests played soccer twice on the beach - it was a lot of fun to watch.

There's an extremely weak open WiFi signal in Chatham bay that you might be able to pick up on the top sun deck of the ship (most of the time I couldn't pick it up). In Wafer Bay there's a cell signal but not for data (I could send/receive texts but couldn't surf or do e-mail). We seemed to alternate moving between the two bays every other day (for no obvious reason) but it allowed me to text with my wife every other day. I used the low-end AT&T International Data plan.

We had one mistake on our trip where the panga driver failed to fill two of the tanks between dives. After analyzing the tanks he attaches your regulator rig but doesn't turn the air on. We were departing for a 15 minute ride to Alcyon when one of the divers turned her air on and saw she only had 500psi. We had just left so we turned around and went back so it could be filled. So then we got out to the site, I roll in first and am hanging at 100' waiting on the captain to come down and 23 minutes later I see him up at 20' but he doesn't come down. And then I see one of the guests wearing what looks like his white tank. Turns out that guest didn't turn her air on until we got to the site and a lot of us had rolled in and then found that her tank hadn't been filled either. So the captain gave her his tank and he took hers and stayed up shallow. Pretty much turned the dive into a cluster because none of us on the bottom knew what had happened.

After getting home I read in Undercurrent that a diver on the Okeanos Aggressor in June died during a dive (swept away in the current, found 3.5 days later in an underwater cave). The crew didn't mention this to us but it doesn't explain the dive briefings for Manualita telling us to stay away from the 3 underwater caves (it was Manualita Deep where he died and that was also where I encountered the worst current I'd ever been in). Pure speculation on my part but I wonder if it's possible that his tank wasn't filled and he didn't notice he was low on air and ran out at 100' while fighting current. The lesson is to make sure you check your air before the panga leaves the ship.

Overall I'm glad I did the trip because it's a bucket-list destination. The warm temps didn't seem to dampen the number of sharks and it was nice not having to worry about getting cold. But it was an exhausting trip, it's an expensive trip, and so for me I think it's a one-time trip.
Websites Okeanos Aggressor   

Reporter and Travel

Dive Experience 251-500 dives
Where else diving Galapagos, Socorro, Palau, TX Flower Gardens, Hawaii, Bahamas, Caymans, Belize, Cozumel
Closest Airport San Jose, CR Getting There Went DFW to Miami to San Jose

Dive Conditions

Weather sunny, cloudy Seas choppy, surge, currents
Water Temp 80-85°F / 27-29°C Wetsuit Thickness 3
Water Visibility 50-100 Ft/ 15-30 M

Dive Policy

Dive own profile yes
Enforced diving restrictions 55 min max, no solo diving, 110' max (although not rigidly enforced)
Liveaboard? yes Nitrox Available? yes

What I Saw

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

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

Subject Matter 4 stars Boat Facilities 4 stars
Overall rating for UWP's 4 stars Shore Facilities N/A
UW Photo Comments Plenty of charging available (110V) outside or in the salon, only one plug supported 220V. Dedicated rinse tanks, plenty of work space, cameras are on a thick foam pad at the front of the pangas (or you can hold your own). Crew takes the cameras off the panga after each dive and puts them on the camera table - it's up to you to then get your camera and place it in the rinse tank. Some divers routinely ignored the direction to not place drinks on the camera tables and more than once I saw drinks dump over onto the table.
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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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