Don't understand the 2x4 on hose covered chains, whats that for? Or how is that setup?
The hose is to keep the chains from wrecking the gelcoat/paint on the side of the hull. The chains are chafe- and ice-proof ways of attaching 2 x 4s or planks that sit at the waterline. The movement of the boat and the water itself moves the planks and discourages the formation of ice against the hull. You can glue foam on the "ship" side of the wood to keep it from marring the hull. Hang them from the toerails.
If you sat in a freezer and poked a glass of water with a stick, it would take far longer to freeze...same idea.