I know this is a ridiculous concept for back country use (or use in general for that matter) but how awesome would this feel after a long day of paddling?

Hot Tub Hammock

Wow - just wow.

From the second photo, it looks like you can attach it to a porch. I could imagine ripping walls down with this.

By Derek's calculator, with 50 gallons of water * 8 lb/gal, + 300lb for 2 people, you have 600lb of inward force in a 30° suspension. More likely, the first picture was 20° - bringing the inward force to 900lb.

I think I'd only trust it in a sand hole.

No underquilt required :)

If you fill it....they will come...