Last winter I watched the ice on lake superior drag a 1,000lb block of concrete about 1/4mile as the ice moved. Someone didn't sink their mooring, it froze in the ice and got drug. Kind of illustrates the power of what you're dealing with... and that was in a relatively protected harbour.
1978 Ranger 28 and a fleet of Mini 12's.
Ropes and rigging and splicing, oh my!