[DRH]

As several others have said, neither a bubbler or circulator will help once the ice starts to break up and blow around in the spring. But there are two primary benefits of keeping some open water around your dock during the winter.

First, the ice expands and contracts to a surprising degree. That's what causes ice ridges, where the ice will crack and one section will ride up over an adjacent section. That same expansion effect can crush a dock if the ice is allowed to freeze solid around the pilings. Even crib docks can be damaged by expanding ice, which has amazing power. I've seen cases where the expanding ice has even badly damaged large breakwaters, dislodging and moving huge rocks you wouldn't think could be moved.

Second, when the lake freezes solid around your dock, especially when the lake level is low, and the lake begins to rise in the spring before the ice melts, the rising ice can lift a frozen dock right off its pilings or cribs, or even lift the pilings themselves up out of the lake bottom.

Many docks not protected by a bubbler or circulator seem to go unscathed year after year, but I've seen enough docks that have been damaged by expanding and/or rising ice that I always try to keep some open water around our dock.