If you are not around and present to keep an eye on your dock, to increase the frequency of ice eater operation ....something like a two day cold snap can do damage to your dock.
For example, after four weeks from Dec 10-Jan 10 of trial and error you think you got the timer just right ...... when on January 11-12 ..... a cold snap brings much colder local temps...... say, with temps dropping into the deep freeze .... the ice eater is no longer running enough to adequately maintain the open water and the ice build up wins the race verses the ice eater propeller keeping the water liquid.....with the deep freeze building enough ice to expand your dock from the legs in the water ..... maybe damaging the dock.
A two or three day deep freeze can do damage without any wind related ice movement ..... just the deep freeze. One can hear the damage happening as the dock structure gets expanded and broken by the new ice .....arrgghh .... bless this here broken dock! ...... ouch!
www.laceyirrigation.com in Moultonborough will do weekly dock checks in the cold winter months, plus there's probably others.
When liquid water freezes into ice, it expands by about ten percent, and ice is much sturdier, stronger, tougher, and more elastic, at 5-degrees, than at 30-degrees. At 5-degrees, the ice is much more difficult to chop up with an ice chopper, than at 30-degrees.