They might have some dive spots near Jaco, but it is the last place I would go to dive in CR. Visibility can be a problem throughout CR's coastal areas but is particularly bad in the somewhat polluted areas near Puntarenas. I'll quote my report from last November, which focused more on west coast locations that also offered nightlife:
Prolijo wrote:
The best areas for diving are probably off Guanacaste on the northwest Pacific coast, the southern Caribbean coast around Cahuita, Canos Island off Drake Bay on the south Pacific, and Cocos Island, eight hours west by boat. Other parts of the country that offer dive opportunities include Manuel Antonio, Nicoya, Drake Bay and Golfito, but visibility can be very erratic. Of the west coast selections Cocos and Canos Island, Drake Bay and Golfito are very quiet and remote. That leaves Guanacaste and Manuel Antonio.
Manuel Antonio, only 3 hours from San Jose, is very beautiful and there is some decent nightlife. The rainforest comes right up to the beaches. It is idyllic.... The Gold Coast of Guanacaste, 4-5 hours from SJ (not sure of the nightlife) also has beautiful beaches but a much hotter and drier climate....The Guanacaste coast also features more dive shops than any other area. Boats head out regularly for the Catalina Islands and the Bat Islands, where visibility ranges from 40-80 feet. Visibility is not the greatest in CR waters due to the nutrient rich river runoff which increases plankton. But the plankton also increases wildlife especially pelagic species such as manta rays, sharks, schools of dolphins and billfish, even the occasional whale. Playa Ocotal, Playas de Coco, Flamingo and Tamarindo are some of the most popular beach towns in Guanacaste.
The caribbean side has some good diving, particularly Isla Uvita just offshore from Limon, which offers lots of tropical fish, sea fans and even an old wrecked cargo ship, and Punta Uvita off of Cahuita, which has CR's most beautiful coral reef with over 35 species of elkhorn coral and 2 old wrecks including cannons at a depth of only 25ft. But there is little dive infrastructure on that coast so you will probably need to bring your own equipment if you go.
Though I have my own tanks and BCD etc. I prefer not to have to lug them around unless I'm driving to the Florida Keys or somewhere local. When I fly anywhere, I find it much more convenient and not very expensive to simply rent equipment where I book my charter. Guancaste has by far the most extensive assortment of dive operations of anywhere in CR. Here you will not find little live coral or reefs, but you will find a huge variety of fish, soft corals and invertebrates a result of the abundance of plankton that thrive in this tropical area (usually near rock formations and the off shore cliffs near islands). We're talking grouper, snapper, jacks, sharks, mantas, as well as tropical species, Cortez angelfish, bright yellow butterflies and eagle rays are common.
Here are some links to some diveshops:
http://www.costaricadiving.net/http://www.ocotaldiving.com/http://www.diving-safaris.com/BTW, if you do a search the correct spelling is "TAMARINDO" or Flamingo Beach
One final comment if you are going to go, the rainy months from May to November are the worst and from February to April is probably the best for visibility.