Excellent, thank you Tom!

Something that hits much closer to your idea is the upcoming Navis from Therm-a-Rest. Damien wrote about it here:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=66917

I think it is going to be a neat bag and plan to look at one next spring.

The Navis is still just bringing back the WM POD 30 probably, with better straps hopefully and maybe a little wider girth for layering that jacket. The first thing I'd do is cut off those straps and see what the weight is. Need to find out the fill weight.

Hard to compare, except in very basic concept. The POD 30 is 2oz lighter (3 oz lighter with excess straps and fabric removed), and a lot warmer. It is an honest 30 degree bag, without a jacket, and has a half zip which makes getting in and ventilating a lot easier. The POD 30 also has a very well thought-out square box construction, which means the down doesn't shift to the sides during use. However, I would be interested to see what the girth of the Navis is. It might be a good option for "over-sized" folks who don't wear a down jacket, but a 45 degree rating is not very spectacular IMHO. I do like the look of the pad attachment.

You could do an easy MYOG version of the conversion with your Cat, becuase it is synthetic. all you have to do is carefully cout out the desired area of the outer fabric on the bottom of the bag, and then cut out the insulation in that area and you are done. If you want it a little neater, you can stitch through the inner and outer layers of fabric where the cut edge is, but you don't really have to, as the polarguard insulation is stable enough that it will not escape. This will weigh some small fraction more than inserting a piece of M50 in there, but it would be very easy to do.

James,

I followed the link that you provided to Sectionhiker and liked what I saw.

The pictures at Sectionhiker mimic the exact way in which I use and "don" my top quilt.

I have an older +20* traditional mummy bag that suffers a little bit from being a little "overweight". It might be a great candidate for this modification. My quilt lacks a hood which requires me to wear some sort of insulation on my head at night. If I modify my old bag I could lose some unnecessary bag weight and gain a hood for those cold nights. Hmmmmmm. ;-)

Party On,

Newton

John. Whatever you do make sure it is machine washable.

I like to zip my down bag open and use it like a quilt most of the time. Having sections without down eliminates that possibility. Fr that reason I prefer to have a fairly snugly cut bag that zips most of the way open and has down on all sides.

I have never needed a zipper. When it's warm I start with either no sleeping bag or the bag draped over me (mostly over torso). As I cool down, I eventually get in the bag and have never overheated that way, but then I would not call myself a "warm" sleeper at my 160 lb weight.

Lynn, I agree...I jumped the gun in the comparison. I'll bet the thermarest won't be the quality of the POD 30, but may have better straps as you mentioned earlier.

Ken,

For sure! L O L

Party On,

Newton