Contact Maria Jose and Ari Barshi at Carib Bic Wind Center once you arrive or before by email. They are one of the best, if not the best, windsurf operations in the town. There you want your son to contact Benyan Barshi, their 17 year old son who also works at the shop. The father is a laser champion, the son knows all about the sports in Cabarete. If you want to write to them in advance, write
caribbic@verizon.net.do
You are coming to the best place in the Caribbean for your son. I know because I have three sons -- 17, 15, and 13 -- and Cabarete is their favorite.
There you want your son to take surfing lessons in Playa Encuentro (nearby), and windsurfing classes at the Carib Wind Center. Perhaps Benyan can help arrange an instructor for surfing in Playa Encuentro. If not, just ask for instructions to get there and go at 7 am and contract the lessons right on the beach. They have equipment.
For the ATV riding, that also can be done. If Benyan does not have a suggestion, contact the people at Iguanamama excursion company, which is right on the main street.
When you can, please share a Trip Report on how your trip went.
http://dr1.com/forums/forumdisplay.php?f=24
Also see
http://dr1.com/travel/cabarete/
And check out Puerto Plata, Sosua, Playa Grande and Playa Dorada on the DR1 Travel Pages for more info on what to do while in the north coast. We recommend you rent a car for full mobility. If not, public transportation works well. Elsewise, taxis are very expensive. If you rent, just avoid driving at night.
http://dr1.com/travel/index.shtml