I am starting a build of the Yostwerks Sea Rider (my first SOF) and was wondering what the "HB" and "HAB" measurements in cm are for the forward and rear deck stringers that run from cross sections 3 & 4, as well as 5 & 6. The pics I've seen of various Sea Riders show deck stringers, but in looking at the offset table, I was a little confused on the measurements for those cross sections.

Thanks,
-Matt