I've just been and used the dive shop 3 times (but I didn't think it was a trek from the lobby, just a pleasant stroll down the beach, or a quick walk once you've discovered the maze of short-cuts!)
As mentioned above, there's no jetty but you just wade into the boat. The tanks are already onboard for you. The staff all seem competent and safe. The dive prices seemed average. The only thing I thought was not such good value for money was the cenote snorkel trip (which was a fantastic trip but should have been cheaper).
I had already been trained but not got my certificate so they asked me to start with the Discover Scuba dive (a 40 minute DVD and a pool session before being allowed to dive). I don't think it's the ideal way to do your first ever dive because it's too rushed, the entry is backwards from high off a hard boat, and you're straight down to 15 or 20 m. Most people on the boat with us who had never dived before couldn't manage it, or used up their air within 15 minutes. But for me it was perfect! My second and third dives were again with the same instructor but we didn't need to do the DVD+pool and it was cheaper.
If you're certified already then obviously you'd buy a two-dive trip instead which as said above is a deep dive first then the novices join the boat for the second at 10:30. I think the price for that is 80US$ but they had so many combinations of trips I can't remember exactly.
Straight after a storm the sea was choppy and the vis was low (not sure exactly, may be 10m) then it improved over successive days. Saw sea turtle
If you want to know any more, or see some photos, then let me know.
