While I ran Service and Parts dept for a local marina we ran every boat on antifreeze, reason is that you never miss a drain plug or worry that you never got every bit of water out of the fuel pump and power steering coolers. It was an issue of insurance that all boats had antifreeze and no worry of cracking a block and costing the dealer money. Every boat was tagged so we knew that it was 100% ready for winter weather it stayed in our yard or went home with customer. We had over the years customers with cracked power steering coolers and blocks that were kept in heated storage facilities, power went out and they froze. It happens a lot. We also live out side of Chicago, IL. Now on my own personal boat I drained and blew out all lines and hoses then added antifreeze.