I went to Playa last year as well, and fished in Cozumel with Capt Alex Euan
It's a lot closer to Playa, and I think taxi and ferry cost around $45. I was there in early June and caught 10 bones, and a few barracudas in about 4 hrs. Alex did a great job, and I highly recommend looking him up!
I believe his web site is www.cozumel.net/fun/flyfishing