Thanks a lot! Pictures really help. 1,000 words. I'll have to get on the hip pads.
The measurement ... from the outside edge of the back of the cockpit rim to the front of the backrest.
Originally in this post, this is what I was after - for both trim, and to make room for my legs:
My distance is about 8"
Scott's (same boat, same weight) is about 5.5" (sits farther back)
Chuck's (not sure of weight or boat) is around 9" (sits farther forward)
Mike, on your WS conversions where's your tailbone/back-of-saddle in comparison to the rear rim and/or the centre of the hip pad bolts?
I've done some thinking and it may be that my seat placement is a little misleading. My actual center of gravity may be as far forward as it is for those of you with your seat 8"+ from the rear rim due to my personal, forward placed caloric storage unit.
Also, after careful consideration, I'd rather err slightly on the "stern heavy side" of level - I'd rather run a rapid on my stern than on my bow despite Mike W's demonstrations that the latter can be fun, too.
As folks have pointed out, I have been known to run stuff on a bow-stall. It's hoot as long as you don't break your boat I run stuff like that because I generally trim my boats close to neutral. Sometimes you pay the price by doing it that way Scott has a very valid point about going slightly stern heavy.
From the outside edge of the cockpit rim to the front of the backrest is 9" in the Big EZ & 8" in the Forplay.
From the center of the hip pad bolts to the front of the backrest is 4" in the Big EZ & 4.5" in the Forplay.
I´m a bit insecure about the right seat position for my Nomad 8.1.
When I´m sitting with my belly direct over the middlepoint of the boat (length/2) I have the feeling that it is bow heavy . On this picture I´m sitting a little bit back of the middle point and it feels better - but it also seems to me that the position now is slightly stern heavy. When I look on the position of the kajak seat I wonder that it was located way behind the middle axis of the boat. Am I on the wrong track with my sight of boat trim for this boat and should consider only the water line of the boat for the middle axis?
Bigger picture: http://www.singletrailz.de/Bilder/Padde ... gersee.jpg
Your help is appreciated.
I am no expert, but I would trim by looking at the water line. I know for my Burn conversion my seat ended up well forward of the location of the kayak seat so I would say you are on the right track. Your trim in the picture looks good to me.
Matt
PS. How much do you weight and how much volume is the Nomad? I am getting a Burn for my wife at 115 lbs and trying to decide between a small or a medium size.
my weight is 137 pounds and the boat has a volume of 68 gallons. The considered Paddler weight range for the Nomad 8.1 is 120 - 170 lbs.
I got for my wife a Dagger GT 7.8 with 67 gallons for her weight of 154 pounds. Tomorrow we will get it and I´m really anxious what difference there is between the two boats!
I think I would go with the Burn S because 72.6 gallons of the Burn M is really a lot.
This is my seat made of Styrodur. I will cut it smaller when I have the correct seat position then laminate it with carbonfibre and glue minicell on it.
I run stuff like that because I generally trim my boats close to neutral. Sometimes you pay the price by doing it that way 
Scott has a very valid point about going slightly stern heavy.
