If you decide to use "lifeboat" style rations, another option is made by Datrex. They are very similar to Mainstay rations. They come in a brick of 18 bars, packed in six separate sub-packs with 3-bars in them to keep them fresh. One "brick" is enough for one person for 3 days. (In theory <img src="/images/graemlins/smirk.gif" alt="" />)

They taste ok, I did a 2 day trip with only what I could carry in my fanny pack, and a brick of these Datrex rations kept me going with some jerky thrown in for variety. They are not supposed to be thirst provoking, but, I always drink lots of water with them for some reason, probably because I've always been hiking when I have eaten them. I think that the Mainstays have more of a lemon cake flavor, these are more like coconut flavor. I happen to like that better than the lemon, but, you'll get bored of either one if it's all you're eating. Then again, if it's all you have, it'll taste pretty good.

I leave a couple bricks in the car kits, and have some on my boat. They take minimal space, and can handle heat, cold, whatever. Here's a link to one place you can get them:

http://www.nitro-pak.com/product_info.php/products_id/554