mold can be an ongoing repeat offender nightmare unless you only put divers on bracelets in it (don't forget to screw in the crown every time you visit it to exercise your watches). Also forget about bronze unless you're in love with patina. As far as ultimate security goes you're probably better off if you cover all the bases mentioned here but there can always be a thief that is a step ahead. Think about the flick Gone in Sixty Seconds but the booty is weighed in grams instead of tons (so much easier to succeed with the heist!).