Lightest Foam PFD

What is the lightest foam PFD available? I need the lightest foam version for pack rafting and traveling with my folding kayak. I would like to use foam for its dual purpose insulation/floatation value.



I thought the hybrids (foam and air) would be lighter than my conventional PFDs but my size mediums average 2 lbs which is about the same as the Kokatat O2.



I have an SOS air PFD which is only about 10 oz without the cartridge but doesn’t provide any insulation value.

These?
http://www.boundarywaterscatalog.com/browse.cfm/4,127.htm



Extrasport also has some light, simple PFDs

Kapok

– Last Updated: Apr-17-07 8:00 PM EST –

may be better for packing away in a tight case than foam. Astral makes Kapok pfds and now some others are, too.

I've never considered the insulation value of a PFD. Just curious if you're underdressing and relying on your PFD to keep you warm? That wouldn't work out too well if you end up in the water.

Lyn