It appears there is a patent application dated 2019 on speed strips. A shame since the paper on them predicted a 0.4% speed increase (32m over 2k) in a
5m/s headwind and 2m in calm conditions.
Scratch that one from the list of things to do to go faster if you live in the USA.
Perhaps someone can explain how it could be accepted given the 2016 research paper and other previous history of their use.
It is, nevertheless, a good description of how zigzag strips and
large bumps can be applied to an oar shaft.