Did you just get your first dock this summer? You must have been very happy when the installation was done, leaving the dock nice and ready for you and your family's vacations down at the lake or river. But the installation isn't the only work you have to do on the dock; you have to get the dock ready for those times when you won't use it, particularly in winter if you live in an area where temperatures drop below freezing. If you ignore the upcoming season, you might find you no longer have a dock.
Install a Deicer
The problem with ice is that it can glom onto the dock's pilings or the underside of the main portion of the dock and then pull those parts of the dock up, down, and around as the ice heaves up. That can lead to the dock breaking into pieces. Ice floes that broke free further up the river can smash into the docks as well, pushing the docks away from the shore.
One fast option is to install a deicer (or a similar contraption called a bubbler) under the dock. These help circulate the water around and under the dock, preventing the water from freezing. They're fast to install, relatively speaking, and they can work well. However, the drawbacks to these are that they don't prevent damage due to large rogue ice floes, and they do consume electricity. If you want a fast solution, and the floes aren't really an issue in your region, a deicer or bubbler could work well. If you're concerned about energy usage, though, they could be more of a drag for you.
Get the Pilings and Dock Inspected
If the dock is not a floating dock, get the pilings and dock surface inspected before fall. Any cracks or weak spots need to be repaired because those can make it easier for the dock to break apart if there's ice heaving. You don't want to show up thinking the dock will be fine after a mild winter only to find that what little ice there was destroyed the dock because of a weak spot.
Remove Floating Docks
If the dock is floating, remove it and store it. If the water under the floating dock freezes, the ice can still grab the dock and wrench it up as the ice heaves up, leading to damage. Plus, ice expands. Not only would heaving be a risk, but the dock would be at risk of damage from the ice compressing the dock materials as the ice expands. And removing the dock means it won't be dragged around during the spring thaw by ice floes.
Install No-Grip Pilings
For non-floating docks, you can also find pilings that are coated in a polymer that tends to resist ice. It's not a forcefield that will stop ice from crashing into it, but it can stop a lot of ice from freezing to the pilings. When the ice heaves, then, it would just slide past the pilings.
Talk to a dock repair company about getting the dock inspected and also about what to do before cold weather arrives. The workers at the company have seen different remedies before and can let you know if they've seen some that tend to work better or worse than others.