They aren't just for keeping your beverage cold, they make you cool. I have some coolies available but feel free to bring your own. Since I allow bottle beer on the boat, please bring a bottle skin with you to help prevent breakage.
Drink Holders are things that hold your drink, and Port Clinton / Put In Bay is no exception. Cans or Bottles: having a neoprene pad between your fingers and the beverage you're holding is the ultimate in drink satisfaction. That's why the Irish C offers proprietary drink holders for purchase. Get a drink holder from Irish C in your hand and ladies give you a wink and a nod as they pass by. Ask the captain for details. (...about drink holders, the last time he got a wink and a nod from a lady was when he was standing in front of Tiger Woods.)