a small gap on your last try posted in 3dm





here another way ... easy to do ... loft between curves

with cap end ... the result is solid

you can easily build a second piece and boolean diff to obtain a hull with various width

( the yellow line is a guide to align the profiles ... not necessary in the Loft command )

and as usual .. better results with profiles cleaned with Rebuild ;)

model joined ... à toutes fins utiles