Has anyone ever tried using one of those foam seats like they sell at Chesapeake Light Craft that sit right on the bottom of a kayak? Just wondering how comfortable they are. Thanks!
Yes, I have been a longtime owner of a CLC Creature Comfort seat.
Is this the one you are speaking of? True to its name, the Creature Comfort seat is very comfortable and supportive. Since it attaches with velcro, you can get extra velcro and then be able to move it from one boat to another. (Currently, Leslie has my CLC seat, and I haven't been able to get it back). One downside is that if the hull of your kayak is significantly rounded or vee-ed, you may need to shim the seat. A moderate shape underneath the seat isn't a problem them. Another potential downside is that you would need to modify it to have it fit in a narrow racing boat).
What about cheap-ish DIY? Old throw-able seat cushions. You know the ones with two small cloth straps. Once the outer cloth goes bad, they are not worth recovering, but if you look inside you will find one or two layers of nice close cell foam.