So here's where I am: I had two different places test my battery and it's supposedly good. I put it back in the skiff and hooked everything up. With everything off, the battery showed 12.76 volts on my multimeter. I cranked it up just fine and at idle, the meter showed 15.10 volts. Seems to be charging, right? I revved it up a little to around 1500rpm and the meter showed 14.5 volts. Drop it back to idle and it shows 15.10 again. Isn't it supposed to charge less at idle? I'm thinking now it may be, as Vertigo said, a rectifier issue. I called around to price one and holy hell they are a lot more expensive than the ones on the old OMC crap I used to run.