I considered that maybe they should be empty. The bulkheads are plywood and glass byt the stringers... well I just don't know. I've heard both sides here and from friends. The guys at wellcraft had a resounding I dunno so no help there.

I'll pray to the sea-tow God and I'm sure it will come to me in a dream.

Interesting enough, the hull is supper solid even with empty stringer.