I've had a CamelBak pack for years (a Rim Runner that I bought in 2005), and for Christmas treated myself to a new [MilTac H.A.W.G.][1] as one of the zips on the old Rim Runner was starting to break and, well, I wanted something new.

I'm very pleased with the pack, but one old issue persists; the 3l of water just isn't enough on 4+ hour hikes in hot weather (I'm in Australia, so it's summer here).

Has anyone had any success adding a second hydration reservoir to a pack? Is there typically space in the main reservoir pocket?


  [1]: https://www.camelbak.com/en/military/gmi-packs/M01005--MilTac_HAWG?color=bd80dd0d597a486395d6339327546e6e