Under very humid conditions, I used a sealable box (something like a lunch box - or a biger version - see the link below) to store camera stuff. You have to keep a packet (or two depending on the size) of silica gel (moisture absorbing stuff - you can obtain some free-of-charge from any pharmacy).
http://www.glad.com/containers/
You can always find better sealing containers.
I suggest using more than one box because if you kept everything in one box and if it starts "leaking" then everything will be exposed to moisture.