Thanks for the advice,all I can say is that I feel I can get glued into the boat with the backrest high and a good thigh brace.
I also paddled 14 miles, some of it into 10-15 knot headwinds with this tsunami tanker, and my arms were fine at the end of the day. (though I have a new pain at the tip of one elbow).
I will give it a try…I am absolutely frustrated with the skirts
Your points of contact really should be feet, butt and knees, not your back.
And the whole point is not to paddle with your arms, but as much as possible with the much stronger muscles of your torso.
That way you’ll be able to do 20 miles with minimal strain on your arms.
Lots of articles and videos here…