When venturing deep into Yucatan's underworld, fresh air left far behind, it's not the time to doubt your life support gear and lose faith.
Google's search oracle pointed me to Munich, so that's where I went and found Tauchsport Manta, a small diveshop run by an elderly man, in whose hands I laid my trust. (DB Bayern day ticket: 19€)
Whereas most open water recreational divers already have a mouthful with just one set, as soon as you get technical, two sets are the basic minimum to get started. Add to that as many stages as required for the mission. In my case, at most one stage should probably do.
UPDATE: Having lost all trust in Tauchsport Manta after several regulator related incidents, this year I went to Gerda's Dive shop.
Here's what Gerda's technician wrote in the maintenance bill:
Bemerkung zur Reparatur: Letzte Wartung wurde Fehlerhaft ausgeführt. Es wurden O-Ringe vertauscht und O-Ringe eingesetzt wo eigentlich Teflonscheiben hin gehören. Teilweise fehlten die O-Ringe und Teflonscheiben ganz. Sitzhalter 1. Stufe beschädigt durch falsches Werkzeug. Schraubverbindungen teilweise Lose.
In short, he confirmed my worst suspicions: Whoever checked my regulators last time can not possibly have been a professional. And that's phrasing it nicely, considering the supposed internal state of things: unfitting replacements, missing parts and damage due to the use of inappropriate tools... Luckily, I can still blog about it.
