A couple years ago I asked this questions and had an excellent answer:
Re: Reflexology and Massage on the beach? Thai massage?
Sep 23, 2011, 1:15 PM
Walk north to the Azul Beach massage tents next to the Mahekial Beach Resort. Ask for Fidel. You'll get everything you want and more for a very modest price..
Are these massage tents still there and have the prices increased much? They were awesome for sure and want to travel back from our stay in Tulum for this amazing experience...