@windswept

thanks a lot for the detailed tips and posts!
although I do not plan such an extensive (and structural) modification than the flying rat is about, it indeed consist of some useful hints!

I thought about the flyer waverpiercing bow, but it's there already: I just should mount the hulls opposite up! on a more serious note, the SC is quite a typical V shape and while extension seems makeable, to add that much volume like nowadays designs would surely mean to cut the lower part of the existing hull open to widen it, something I really don't want to do. I would have to extend it to an amount people might call it team phillips afterwards ;-)talking about this 'wavepiercing' hype, I am pretty sure the SC 20 is much more wavepiercing (and less pitching) than my Flyer A-cat ever was... the Flyer shape has much more lift generated planning tendencies, that's where it's major advantage becomes evident.

your comment on the scarf joint is interesting! what exactly does it mean/look like?

do you think stock foam(closed cells) like used for underground building insulation (mostly grey, green or blue) would be suitable? I have seen the ship-models used for tanktesting also uses this (while not encountering any side forces so).