My Yanmar 2gm16 also specs 30wt in the trans. it appears to always have had 30wt, being as PO was OO too!
I wonder if Caliber felt it better to have ATF in the trans vs 30wt, and as such, when they installed the motor/trans, they put in ATF. A thought, nothing more!
She drives me boat,
I drives me dinghy!