: Given that paddle blades need to be thin and resistant to
: splitting, is there any reason - apart from weight - why marine
: plywood is not used or rarely used? I would have thought it
: would save a lot of work and produce a more robust paddle.

I built several "spoon" paddles many years ago using 1/8" aircraft plywood from a hobby shop.
Mine were knock off's of my racing "Lendal" (pre-wing). I raced and toured using these cheapo blades (no fiberglass),
and that included the National championship. The paddles lasted at least 10 years before being replaced with GP's.

The only pic I could find is from pre-digital camera days... Tom