I have fished for bones in Cozumel. There are a few good guides in Cozumel itself. Cozumel is just a short ferry ride across the channel. The guides I went with were. Aldofo Sr. and Aldofo Jr. Castillo.
Senior doesn't speak much english and I don't speak too much spanish. But enough for him and I to communicate throughout the day. He got me into quite a few bones.
Here is their contact information as it appears on their business card.
Asociacion de Prestadores de Servicios
y Guias Profesionales de Pesca
Deportiva en Cozumel, A.C.
Adolfo Vazquez Castillo
GUIA ESPECIALIZADO EN LAGUNAS
BONE FISH VIAJES ROBINSON CRUSOE
65 Av. Bis No. 632 X Hidalgo y privada Hidalgo
Fracc. Cuzamil Cozumel, Q. Roo, Mex. 77624
Tel. 872-5622 evenings
Cel. 044 987 87 64 053
Adolfo Sr. and his son Adolfo Jr. were just fantastic and I sure wouldn't have any problem recommending them to anyone going to Cozumel. They said they also fish for Permit, Tarpon, Snook and other fish depending on the time of year and of course the conditions.
They said that the best times for bones is during July, August and September but the tourists aren't there then. Apparently it's hotter there then, but the wind doesn't blow as much then.
Here are some flies that I use for bones with confidence. The one I had the best luck with was the top right one.
Below is my all time favorite bone fish fly. I tie it on a size 8 or 10 (yes it's small) black bone fish hook or stainless steel hook. The middle is sparce natural squirrel tail. The sides are tips of natural grizzly hackle. The eyes are gold bead chain. I find the bead chain sinks the fly, but does not make a splash in the water like lead eyes. I usually do have some with the lead eyes for deeper water. But I find the bead chain one's work best because they don't scare away the bones when it hits the water. I usually use the bead chain ones up to about 3 feet of water. Any deeper and I switch to the lead headed one's.
The pink I used in both these patterns below is pink calf tail. Try finding that one. It was not easy. But you can subsitute any variety of things to make the pink. EP fibers, floss, or squirrel tail.