The nice thing about a backpack based system is that there is extra room in there.

(for food, my jacket, binos, DW's fancy sun hat, collecting trash, umbrella, etc. and so on...)

I just got a new pack for DS tonight but didn't get a camelback. I got him a regular pack (Broadstone, not sure which model) because he's already carrying a lot and finding water in our area isn't a challenge. Making it drinkable is.

I'm building one of these to keep in the truck for unplanned hikes...Which I do pretty often

I was going to say not to leave water in it. Every time I have done so, even purified and refrigerated, it has gone bad on me.

Very nice! You've packed a lot in there.

I picked up a new 30 litre pack today from MEC. It is priced decently and has features that compare with similar BD packs which are much more expensive. http://www.mec.ca/AST/ShopMEC/HikingCamping/Packs/DayPacks/PRD~5024-833/mec-spirit-30-daypack.jsp

I normally carry a TNF Recon bookbag for everyday carry. Although rated at 30 litres it is a 25 litres at best. It is good for my evening University classes and for geocaching. It is somewhat useful as a dayhiking bag but not large enough for a quicky overnight bag. The larger 30 litre one will do just fine. (I actually looked at a 40 litre bag too but it is just a tad too large for airplane packing.) My thoughts are that I will keep this pack loaded up and ready to go for longer day hikes and warm overnighters.

I also want to create a 2 stage BOB system. The 30 litre bag will carry the immediate items and a second larger 50 litre bag will serve as a mainstay. I have a modular philosophy to my equipment. For example, my FAK is a modified AMK .5 and the mini survival kit is a modified AMK DR pocket kit. I can put one in each leg of a set of cargo pants. The BOB will also be modular with the smaller bag serving the immediate needs and the second will encompass the things the smaller bag would miss. Both will be reasonably light. Light is easier to carry and if I have a female or youth partner then I can have them be outfitted as well as a team. My reasoning is that if the BOB(part A) is in the vehicle and BOB(part B) is stored in the garage and ready to go I will have additional flexibility.

Now off I go. I have to make a list of what to put into each bag and test out the loading.

Snake -- yes, I add water just before the hike. ( I also carry a water bottle -- or 2 -- in the cab.)