Shelf life of ingredients?

I'm figuring the pros and cos of various ingredient types and kits for sailing long term. Each question assumes a 60deg constant temp (warm sailing waters) and darkness.

How long do you think a coopers kit will last?

How about 1/2 a coopers kit once opened?

How long will canned extract last?

How about vacuum sealed DME?

Fresh, unground grains stored in an airtight bucket?

Tasty homebrew on a boat full of thirsty sailors?

BrewOnBoard

coopers - Until the expiry date on the can
1/2 coopers - not long a few days maybe a week
canned - until the expiry date on the can
DME - a long time probably longer than you will need
grain - it will last a long time but the space for the extra equipment will probably not work on a boat.
Homebrew - it should last the night of if you brew everyday you can have a steady supply