Gary, I played a three month summer season on the north coast of Crete, so similar conditions to those you're experiencing now. This was back in the day when I was toting my trusty old Hammond,

I was concerned about salt-laden condensation, but there was never a problem with corrosion of delicate parts. Maybe the organ fell into the same category as Russ' MS-60s, i.e., TANKS. I think your Yammy will be okay, too.