[C320-list] Changing transmission fluid

[Bruce Stumpp]

I'm getting ready to change out the transmission fluid but am not sure what
fluid to use or where to get it (checking at the marina tomorrow).   Our
C320 is a 1999, hull #674 and has a Yanmar engine. Stamped on the
transmission is Model: KM2P, Oil: SAE20/30 HD and  Kanzaki (which I believe
is the brand).   Does the oil reference mean "Use 20 weight HD or 30 weight
HD" or does it mean "use 20W30 HD? Anyone out there have the same trans
and/or know the answer?  Is this something I'll be able to find in an
automotive store or do the marine stores stock it?

Bruce Stumpp
#647, Adventure
Frog Mortar Creek, MD