I am puzzled how anyone managed to attain customer satisfaction with the Aqua-Inn Dive Shop @ The Grand Sirenis, because I certainly did not. It might of been a language barrier (I only speak and write enough Spanish to survive), but it seemed like each time we booked a dive with them it became an extraordinary hassle and it almost seemed they would rather not take our money. Every time we showed up to pay a bill or book another dive they had this expression on their face like, 'oh hell, what now'.
Additionally, mathematics didn't seem to be on the curriculum for a dive shop owner. The woman -who I assume has an equal partnership in the company with her husband-, overcharged us $120 (We only purchased four dives and some rental equipment). If the egregious error hadn't of been caught by us it would be charged and never spoken of again. To me it also seemed intentional because she believed we didn't know how to calculate the exchange between pesos and usd, but that will never been known. They also fell short on supplies, too many time delays too describe (some over 2 hours), and spoke in bad form (foreign foul language while discussing our dive trips) before they realized I understood them.
I understand that I may be a little harsh towards their management, but I have never been treated so poorly by any other dive shop. It should also be noted that while we were there no one else that stayed at the hotel and used their services had a different opinion than us about their inadequate satisfaction. We ultimately switched to the Akumal Dive Shop which was much more organized and actually treated us like paying customers.