+1 on the Boat ration bars.
They are made to hold up to temperature extremes for 5 years (rated -40 to 300 deg F or -22 to 149 deg depending on the brand). The Datrex, Mainstay & Mayday ones taste decent. The ones that Westmarine sells suck (plus they gouge you on price). The 3600 calorie bars go for $5.50 to $3.95 from various vendors online, Westmarine jacks you for $10 for a single 2400 cal bar.
The Datrex tastes like Coconut cookies, the Mainstay tastes like Lemon cookies, the Mayday like Apple/Cinnamon.
New Millenium also makes a 5yr shelf life ration bar in 400 cal sizes that come in different flavors (perfect for picky people/kids) they have orange, lemon, cherry, apricot, tropical fruit, blueberry, raspberry and vanilla.