It depends on whether you are right or left handed. If you are right handed, your right arm is probably bigger and that is the one you want the girls at the lake to see first. This would mean starboard side steering........

Or your right forearm is bigger. . .

My Grandpa told me the real reason when I was a kid and Grandpa's don't lie. So I will end this bebate for you guys. LOL, Grandpa said that on most inland lakes boats travel counterclockwise so the helm is on the starboard side of the boat that way when making a turn the portside goes down to the water surface and the starboard rises up out of the water. By being on the starboard side the driver is at the highest side of the boat and can see any obstructions on the starboard side and portside. So thats the real reason sorry to burst your bubbles LOL.

My Mailman says.......Hey, you get in and out of this truck a million times a year loaded with mail and see where you want the drivers station! I couldn't even get to the powerboat question with him.(He's a boater) Nasty prick he is!