I'm planning my first thru-hike, going to tackle the Sheltowee Trace in August. It looks like I'll need to cache some water for about 150 miles or so (many of the water sources are unreliable year-round, and it will be August in Kentucky!). I've never planned a trip where I had go more than a day to find a water source, so I'm a little tentative about this and was hoping to get some experience and advice from you guys and gals...most importantly, if I drop a gallon of water in the woods, will it still be there when I need it, or do I need to recruit somebody to drop water at specific locations so it's not out there for more than a day or two? Also, much of the trail is on land managed by the Forest Service, do they frown upon leaving water caches (it IS plastic, after all), even if you pack it out with you as you go? If anybody has some experience or tips to offer, it would be much appreciated.
Where I hike the most, caching water is the rule. Hopefully you can plan your caches near a road. I like to use sealed gallon jugs bought at the store for caches. The seal insures the cache hasn't been tampered with (seen that happen) and those jugs can be stomped down flat for easy carry, and they weight practically nothing. The lower half of a jug makes a good wash basin, too. I write my contact info, date, and likely pickup time on the jug with a sharpie pen. Then camo and hide the cache completely from view, well off trail. If I'm carrying a GPS, I'll set a waypoint for the cache....but also make some notes and mark compass bearings to two land features. My GPS put me 100 yards off of one of my caches and the compass found it, so make sure you write down plenty of clues. You'll be tired when you get to the cache and searching for your own water is no fun. DO NOT cache food with your water. Animals will 'un-hide' your cache, guaranteed. That's about it.
Loc: Central Texas
I prefer the bladders from boxed wine. They are very durable, and come in 5 and 9 liter sizes. When empty they roll into a package about 2x4 inches weighing only 2.5 oz for the large size and a little less for the 5 liter. So they are easy to pack out. And they are free.
I cash them away from the trail and out of sight, and camouflage them with pine needles or other leaves. Since they lie flat, they are easy to hide. In the desert, I cover them with piece of khaki or chocolate chip camo cloth.
How so? Do you have a source for those other than buying/drinking a LOT of wine? Guinness man, myself. If it came in bags, I'd buy it! How do you make them 'tamper' proof? They are clearly lighter than store bought plastic jugs, but I've seen peoples water 'messed with' before.
Loc: So. California - Murrieta
I also cache water in the desert. As Dryer posted,I use the store baught gallon jugs. I've been doing it for years with no animal problems. I also note on the jugs date and name and hide them from casual discovery.
Loc: Central Texas
Merlot in a box? Yeah. I don't drink a lot of wine, but they accumulate over the years... parties and so on. No water container is tamper proof. I rely on concealment away from the trail. Never had a problem.
I haven't had to cache water along a trail yet, but if I do, I will use the wine bags. I can't stand the stuff (wine, that is), but I have some friends who drink it, so I do have access to free bags. It might take awhile to stockpile them, but hey, free is free!
I will do as suggested, by hiding my caches off the trail and marking them with my GPSr. I will also write down clues/directions as to where it is and keep that info with me as well.