Originally Posted by gargoyle
Try suspending your "underquilt" under the hammock on shockcord. It allows the bag to float around the underside of the hammock, and helps it not get compressed by your body weight.
You may find that the full size sleeping bag/underquilt is to large and you may need to cut it down in size to work well with the hammock.
Take a look at the underquilts available from the vendors here. It may give you an idea of what sizes of uq are popular and work with a hammock. If sewing and diy are not option, consider purchasing an uq.
I started learning to sew (I'm STILL learning) shortly after I left home, back in the dark ages before the transistor, when vacuum tubes ruled.
Since I no longer back pack, weight is not a concern to me, although bulk is. Since I sleep at a 45 degree angle in the hammock, the UQ would of necessity have to be at least four feet wide at the greatest point. Were it to be insulated throughout, it would be quite bulky. My initial thought is to make an outer wrapper that covers the hammock bottom for wind protection and alignment, with an insulated area that covers the portion of the hammock in which I sleep. I'm going to have to think on this some.