: I've been playing with a surfski design at 20 feet long. Just for
: fun I shortened it to 16.5 feet (to sneak into a local race in
: the "recreational" class)

: According to Kayak foundry the drag is nearly identical in my
: target speed (6 knots) and the drag is far less at speeds under.
: I'm not surprised at the the lower speeds, but I would have
: thought that the 6 knot drag would have been significantly
: higher.

: The stability took a huge turn for the worse... but I can live with
: tippy.

: Am I missing something? In the real world, can I take my surf ski
: plans and build a shorter ski and eat my cake too???

Nope, or it all depends.
Everything is a trade off.
The shorter the hull the lower the possible hull speed.
The longer the hull the heavier and so slower.
Given the same person paddling, the longer can attain a faster speed, the shorter can hold a slower speed better.
The stronger the paddler the closer he can come to the hull speed for longer times.
Where you fit into this spectrum will answer your question.
JohnK

: Rob