Cocos Island
I had the chance to make several trips there. It was the greatest experiences of all my diver life! The island beauty and the underwater wildlife are really astonishing...
Bat Islands archipelago
I could only dive there a couple of days but it was an amazing stay. The visibility is very poor in these greenish water. Lots of nutriments are around there and it attract tons of fishes : from jacks to Manta rays and bullsharks...
Trek in the forest
When Treking in the forest of Costa-Rica, you can see lots of insects, frogs, birds, monkeys and even crocodiles! 
You can check my travel guide to get some advices about this destination
More informations
My 2 trips were done aboard the Sea Hunter. The boat is the most comfortable I ever saw. There are plenty of space and power supplies for all the camera and diving gear. The crew is very professional and the food is excellent. We had a very pleasant travel between Puntarenas and Cocos with a calm sea. Diving in Cocos is one of the most astonishing experiences I ever made. The visibility is perfectly clear and the fishes are everywhere. Although you can see frogfishes or small stuff, Cocos is not known as a macro spot. It is thus, a paradise for big stuff lovers :-) If you like to see marble rays, hammerheads or plenty of white tips sharks hunting at night, this is the right place to be! I also had the chance to see a huge manta ray and a mobula ray that turn around us during 15min when we made the safety stop. Among all these big fishes, what is amazing in Cocos is the huge schools of jacks and snappers that are all around you... Except from Sipadan, I never see such huge concentration of fishes in any of my previous travels. This trip is definitively one of my best souvenirs. The Cocos Island is very impressive, with all the birds flying around it... You can see here one of the last rough lands on Earth... This makes you feel so free!

Deepsee: I also had the chance to test the "Deepsee" submarine that was on the boat during our cruise. This submarine can handle 3 persons and can dive up to -350m deep. Diving in a submarine is one of my dreams when I was a child... and I made it, thanks to the Sea Hunter team! The experience of diving in a submarine is priceless (but my purse feels much lighter after this) and I could see species and landscape that we cannot meet as a "normal" air/nitrox scuba diver.
Beware, since 2016 park regulations have changed and restrict scuba diving in Coco: 
• It is now forbidden to go into the water during a baitball when dolphins are part of it. 
• Night dive at Manuelita where white tips are hunting are limited to 10 divers max per night. 
To "activate" displaying of an arrow, use its property "Visible"