: Has anyone here ever taken a truck or tractor inner tube
: and put a stretcher frame in it to shape a Kayak-type floating
: device?

Perhaps not as crazy as it sounds! I have 2 Stearns IK-95 inflatables, 8 foot fun toys. They aint much more than what yer thinking about. Track pretty well, with some addl weight in the bow. Not a real kayak, as such.... but ive had great vacation experiences, pulling these out of the trunk...crossing longways on a glacier lake in Maine, beating the storm back to shore....watching sand sharks at bottom of Cap Cod bay...Just fun to have.

Here are some pix i found that are as good as are out there.

http://www.google.com/imgres?imgurl=http://images.craigslist.org/5Ke5Fe5Md3K83L93Hdc71534316d6aaa11e56.jpg&imgrefurl=http://medford.craigslist.org/boa/3112410417.html&usg=__ky_wnyhXGb7_JCf3A0_llpyn354=&h=450&w=600&sz=75&hl=en&start=3&sig2=yke4Kr8jyHl-CpDWKk1nqw&zoom=1&tbnid=l7f7DbJ2hwdYyM:&tbnh=101&tbnw=135&ei=sCAEUK62Lum30QHE8Y3sBw&prev=/search%3Fq%3Dstearns%2Bik-95%2Binflatable%2Bkayak%26um%3D1%26hl%3Den%26client%3Dsafari%26sa%3DN%26rls%3Den%26tbm%3Disch&um=1&itbs=1

if you want to pursue this and need actual dimensions, PM me

kOz