I am looking at buying an off shore cat with SSM#3 drives.As the boat is currently winterized I told the owner that i need to hear the engines running. he said that was ok but due to the short time period they would be running that there was no need to summerize I balked at this as i fear impeller damage but im not familiar with the SSM Drives and the engines are supercharged. any help with this would be appreciated. I know on Bravo drives.. Bye Bye lower impeller without water circulating is the same true?

Only alphas have a pump in the lower. Bravos, trs, Ssm all use a belt driven pump on the side of the engine. No water goes through a trs or Ssm.