I several pairs of GI cold weather gear, and some after market fleece sweats. For the pants with no stirrups, I put the pants on over the sox, then use an old pair of blousing bands to make sure they stay put. The wide velcro jobs, not the cheezy green rubber bands.I have a couple of pairs of the military surplus arctic weight long johns. They are light as a feather, thick, and warm. I wish they had stirrups but what I do to help keep them in place is put my thin polypro liner socks on first, then the long johns, then my thick wool/polypro stocks, trapping the long johns between the two pairs of socks. Works great.
I was wearing them today and was in the float tube for six hours this morning with my leaky old waders taking on water the whole time. It has only been a couple of weeks since ice-out. I was wet up to both thighs but still comfortable.
Guido.....I am curious of what tube you have that has nice high seating? ThanksIt depends on how much of you is in the water. My current tube has high seating so only below the knee is below the water line so tall wool ski socks do the trick even with my Orvis Ultralights with neoprene booties in 45 degree water. If you have the older style "full immersion" seating then full neo waders with fleece layers is required.
Patagonia puts out a Nanopuff pant that works great. Problem is they are expensive but fly shops often discount these. A pair of merino wool long johns underneath will have you really warm. Used this many times when water temps in low 40's when in a tube or up in BC when it's cold. Expensive but will last forever.I am curious what others like to keep warm inside waders when tube fishing cold high mountain trout lakes.