Sounds like advice from somebody who wants to sell paddles.
In practice, 4 cm (216 to 220) makes hardly any difference.
Materials and blade shape cause more substantive effects.
If you don't own a paddle yet, I advise buying one with
adjustable feather angle, once you settle on a length.
Werner makes these, but so do other manufacturers.
WW paddles have been sized in 2 cm increments for many years. They,
like touring paddles, are getting shorter.
Unless you order custom, you can only buy 210, 220, 230, and 240 most
places. I'm 5'11" with long arms in a skinny boat and 220 is good for
me. Actually, my Cricket is a 215 after it broke at the ferrule and I
fixed it. My wife is 5'3", also in a skinny boat, and Greg recommended
a 210 for her.
Steve
Could it also depend on whether the user wants the equivalent of high or low
gearing?
I use a short (203 cm) paddle for surf because after I kick out of a wave I need
to paddle really hard to accelerate out and over the next wave before it breaks
on me. The shorter length acts like a lower gear on a bike: more power with
less muscle but more rpm's.
For fitness paddling I like about eight inches more length because I can go
further per stroke.
Seems to me like my own formula for paddle size involves my upper arm length (to
make the 90 degree "U" grip with paddle held overhead) and the "gear" that I
want.
--
PeteCresswell