Easy to do
Easy to steer, short turning radius
Solid drive connection with water
Butt and back don't get sore like in a kayak
Handles rough water really well
Easier than SUPing
To develop the fishBOAT, Billy Roeseler told me to start with a human-powered craft, in which I used myself as the engine. Using this as a platfom, I sought to reduce the number of parts to a bare minimum. Even pedals, a drivetrain, chains, sprockets, etc., involve too many parts. Parts are bad! I went through a number of variations (bobcraft, fishBOOT). Click here to learn about why I picked this problem to work on.
Eventually, I settled on the fishBOOT, so called, because you wear it, like a boot. It has only one moving part: the entire hull. You rock your weight, forward and back (or up and down, in the two-person version), which causes the hull to oscillate. It has a fin, attached to the hull with a flexible tendon. Oscillation of the fin generates thrust and the craft goes forward. The drivetrain basically consists of one moving part, plus the tendon.
It is easier to do than stand-up paddle-boarding. I am working on a new, even simpler one-person version which steers from it's nose.