here's a real stupid totally cheap idea using the way drybags sorta operate but applied to a dumass float bag.

you get a DOUBLE strength drybag as well as the original floatbag all for the price of the cheap blowtube ONLY floatbag.

you buy the looooooongest cheap (rectangular if possible, better if not tapered)float bag you can, blow it up 1/4 full and INVERT the far end inside the bag so the far end now touches the near end and the bag is now only 1/2 as long. fill this inverted part 2/3 full of gear and fold the ends flat down. then place down say 20inches of 1in wide webbing and fold this end over say 4 or 5 times over the webbing(or maybe a line'd be ok) and tie the ends of the webbing togther tight and you have a 2 layer drybag.

let out the air in the tube, slide the bag into the yak and blow up using the blow tube. 2 for one! the drybag is double thickness everywhere. only problem is the gear is not lockedin place and can flop around a bit.

-might even work

-mick