I have designed and built several stitch and glue pedal powered kayaks over the years. I love them. I think they are faster than similar sized oar powered kayaks. I get complements and lots of interest from people whenever I bring them out.
Yet these types of boats have never really become mainstream. The few factory pedal powered boats and drive units out there are very expensive, I assume because the economy of scale just isn't there to drive the prices down.
Any thoughts about why these types of boats seem to remain specialty niche type things?