They're only about maybe 6"x12" and a few inches deep. Big enough to hold your cash, passport, some jewelry, plane tickets home, things like that.
There is a piece of paper in the cabin telling you how to use it that specifically says DO NOT use your Sail & Sign card to lock and unlock the safe because it will deactivate the Sail & Sign card AND the safe. That's a bunch of crap, it will not do either. I think they just don't want you doing it for security reasons.
I carried my driver's license around with me on board in case I got carded anywhere, and I also used it as my safe key. Anything with a stripe will work, all the safe cares about is that the SAME mag stripe is used to open it that was used to lock it.
I believe it's "don't use your room key", because if you do, the master keys that are used to open the doors to the cabin by the steward, will then open the safe! I think they are 99% good people, but there is always that 1%, and with my luck, he'd be my steward. That's why I usually take some kind of room key from the Holiday Inn, or something like that to use for the safe. Also, if you loose that card, it's no big deal!
Have a great cruise,
I don't think that's the case - even though the steward's card will open my door it has a different mag stripe from my Sail & Sign. As a matter of fact, the one time I DID lock the safe with the Sail & Sign just to try it out, my wife's Sail & Sign (which opened the same doors) would NOT open the safe.