Scuba Diving is great in the North West portion of Costa Rica. I highly recommend using Playa Tamarindo as your base camp for scuba diving. I did a lot of research while I was there and the best dive shop I found was in Playa Flamingo which is only 15 minutes away by car or they will pick you up.
The place is called Aqua Center Diving and is a Padi certified shop with several instructors employeed. They actually had the best boat in the whole Marina and price were average if not cheaper then most other small places. They take you to the Catalina islands which has most dive sites then anyone could do in one week. Great place to see rays, eels, and sharks in the deeper waters.
Equipment: They have full rental equipment there which is good because the small local airlines charge for anything over 30 pounds of luggage. Their dive boats can hold up to 15 people with 2 tanks each. Most other dive boats in Costa Rica can only hold 1/2 that at best.
The beaches along this part of the Nicoya peninsula have a very gradual rise from the sandy sea bed onto the heaps of sand on the beach. Behind the beaches, and separating the two beaches is a estuary and dry marshland. The beaches create a gentle curve along a several mile long stretch. Like any good surf spot on the Pacific Ocean, the waves can be large and in regular patterns, and at these beaches the ride can be a long one too. I didn't observe much crosscurrent activity despite the location near an estuary, but the waves break in both directions. Playa Grande seems to have the edge on quality surf waves over the more popular Tamarindo Beach.
Equipment: I didn't have time to check out the opportunity for rental boards in Tamarindo, but I'm certain that this is a possibility because I've seen it elsewhere in Costa Rica. Good luck to those bringing boards over the washboard gravel roads from the main highway on the Nicoya Peninsula.
Playa Langosta : Right and left river mouth break. Works well on big swells. Breeding ground of the giant sea turtles.
Playa Tamarindo: Right hand point and a right and left river mouth break. 5 minutes by car or 15 minutes walking ocks, not for beginners.
• Pico Pequeño: rights and lefts in a sand bottom, small size swell.
• Pico Grande: rights over rocks, big size swells .
• River Mouth: rights and lefts in medium level surf .
• Henry's: very heavy left over rocks, not for beginners .
Little Hawaii : Right rock points. Breaks best on W and NW swells 30 minutes by car or 20 minutes by boaT.
Playa Avellanas: Good rock bottom right in front of a small estuary. Small barrels 30 minutes by car or 20 minutes by boat.
Playa Negra: A right reef bottom break, south of Avellanas. Can hold size 40 minutes by car or 30 minutes by boat.
Playa Grande: One of the best surf spots in Guanacaste 25 minutes by car or 10 minutes by boat.
Witches Rock :Very good lefts and rights on the right side of the estuary mouth from mid to high tide.
"Roca Bruja" :Waves range from 5-10' depending on the season and swell. Beautiful environment: monkeys, coyotes, raccoons and deer. 2 _ hours by car or 2 hours by car and boat.
Ollie's Point "Potrero Grande" : Very high quality rights at a river mouth. There is a left point break on the south side of the bay Only accessible by car and boat 2 _hours.