We just installed a high-output alternator and I want to use a better belt than the smooth Yanmar belts. I did this before, 12 years ago, on our old boat, but I don't remember exactly what the "better" belt was. Gates? Something with grooves that has better grip. It seems like it was fairly easy to get, but I don't remember where. NAPA or an some auto parts store?

Can someone point me in the right direction again?

Thanks.