The scuba diving in Costa Rica can be a great experience if you have good conditions. After having over 100 dives in the Playa Hermosa area and hundreds of other dives throughout the Caribbean Mexico, Belize and Galapagos, I can safely say that the most accessible diving with the most underwater wildlife is in Costa Rica.
There are dozens of great dive sites located a few minutes from shore in Hermosa around “Monkey Head,” a large offshore rock outcropping. These sites are usually in the 40 – 60 foot range in depth and are easily accessed.
The underwater wild life includes canopies of fish of many species. So much so, at times you literally swim through a wall of fish. If you search about the bottom, there are many starfish, lobsters, eels, and small reef sharks. Occasionally, a larger shark may pass by, including hammerheads and bull sharks. If you look closely, you will find stone fish, octopi, and a rare sea horse. Nowhere else but in Costa Rica have I seen schools of puffer fish which makes for a great experience.
There are some downsides to Costa Rican diving. The weather can change suddenly. If a cold front comes in, the water temperature can drop 15 degrees overnight, requiring you to wear thicker wetsuits, gloves and hoods to stay warm. Even in warmer water, there are thermaclines in which the water temperature will drop suddenly by 10 or more degrees. This is usually preceded by a “crystallization” appearance in the water as if you about to swim through a thin sheet of ice.
There is no coral in Guanacaste. There is only rock and sea grass. The visibility is less than you may expect due to the large amounts of nutrients in the water. During times where you have rougher water or currents, visibility is reduced further. And, due to the large nutrient presence, your equipment will smell much more, including the worse foot booty stench ever!!
You need to be prepared for colder water diving. I almost always require a 3mm suit with gloves and I am one of those “warmer” people. Only a few occasions have I been able to use a shorty and those were some of the best ever.
If you are an advanced diver and are willing to travel further, the diving at Catalinas and Bat Islands. Diving at Catalinas involves dealing with deep water, surge, and current. The effort is worth it when you get to Shark Alley where sharks congregate along a sandy bed at the ocean bottom. Bat Islands is a pure, very deep, drop down where you stay still looking for large animals to appear. On good days, you may see manta or devil rays, hammerhead or bull sharks, etc. It is a hit and miss thing.
While diving in these areas, you will see rays jumping out of the water and flopping through the air. It is common to have dolphins hanging around the boat wake while traveling through the area. My personal favorite is Punta Gorda which is sometimes used as a second dive following initial diving in Catalinas or Bat Islands.
My two favorite dive shops have been Sirenas Diving and Rocket Frog Divers, both located in the Coco area.