Zip Lock bags simply do not work for any period of hiking.

I tried them out in my water backpack which is what I use to hike along the lake and river and has the chance of getting splashed or wet.

After maybe 5 miles the bags were rubbed through in some places, and others had opened. Double bagged, and not, zip-lock brand heavy duty and normal.

Bags simply are not strong enough to move around in a backpack.

They have THICKER plastic bags not sold at grocery stores that work... the map carriers that are for hiking are nice too.

I store stuff in my nalgene, works great.