1. Check your dock cables. In shallow water the ice will harden around the dock areas and as it melts, it can push your dock further out. Check dock cables for any weakness and repair or replace as needed.
2. Depending on the lake, use a dock bubbler that will keep ice from hardening around the dock.
3. Ensure that your dock is covered under your insurance plan. Some carriers add it under the 'Other Structures' class in your coverage/liability limits. Make sure the limit is high enough value to cover the dock.