Welcome to the Cruisers community.
We have ice form on our lakes in Montana due to Canada exporting cold air.
As to mooring buoys in icy water, of keen issue is whether the ice sheet will flow and destroy the floating buoy that is trapped in the ice or and / or break the retention chain or drag the buoy anchor
We have watched large sheets
of ice break away and begin floating across the lakes and when their massive weight impacts a dock
or a even a rock breakwater sheltering a marina, the huge berg just shoves them aside crumpling the structures.
There are special winter buoys that are thin and long and look like sticks which thin profile tends to allow the stick to be pulled through the layer of ice when the ice sheet shifts about thereby offering less pulling force on the buoy and the retention chain. An example of winter sticks can be found at the link below.
An alternative is to use GPS
or to triangulate from bearing on shore to record
the location of the mooring anchor such that one can remove the buoy before winter sets in and then dive down to recover the chain and attach the buoy when boating
season starts anew, say in mid May, or June. The four seasons in Montana likely being much like Canada's, being June, July, August and Winter.
I know of one person that moors their boat on the lake and their practice is to remove the surface floating mooring buoy before winter but attach a different and smaller float further down the chain so as to cause the chain to be only partially raised from the lake bed
and then when they desire to recover the chain at the beginning of the boating
season he dives down and can easily locate the chain because there is float suspended say five or ten feet from the bottom, yet the float and chain are kept deep enough to be never caught up in to the surface ice even though the lake level is lowered by about ten feet in the winter months to provide for flood control capacity and to cause the ice to be kept away from the shorelines to mitigate erosion and to mitigate against damage to docks and breakwaters. Whereas if his mooring retention chain is just dropped to the lake bed
after removing his mooring buoy it can become very hard to spot when diving
down to retrieve it and he has to dive all the way to the bottom to gain a hold of the chain. But with a float raising a part of the chain he doesn't need to snorkel so deep. The water can be very cold early in the season, especially at depth
so he doesn't like to spend much time retrieving the retention chain.
I can attest that time spent in the water early in the season is no fun, e.g, 40 degree water truly hurts and can be very dangerous even for a few moments. I find it literally takes your breath away and it gives me intense pain in my skull if I fully submerge
. My lips get chilled quickly and it becomes hard to form an effective seal around the mouth piece of either a snorkel or a diving
respirator. It becomes frozen smile time, but you are not really in a smiling mood. One becomes hypothermic in a hurry.
Another approach is to tie a rode
line to the mooring chain when removing the buoy for the winter season and to run the line towards the shallow water near shore or even up onto shore and then use that line to retrieve the chain that is in deep water at the beginning of boating season. One boater attaches the towards shore end of the rode
to a small anchor and then just walks out to where he placed the anchor and rode in the early season when the lake is drawn down to provide for flood control containment before the Spring freschet begins to flow and the lake refills to its summer depths. He locates the rode and attaches a float and remove the anchor and when its time to place the mooring buoy he just gathers the float from the surface with the rope
rode attached and retrieves the retention chain and then attaches the mooring buoy for the boating season. That way he never has to get into the water until the lake warms considerably later in the summer.
Our water temperature just keeps dropping what with the minus degree nights, so this morning it is presently down to 30 degrees Fahrenheit, and is iced over in most of the major bays but the lake has not fully frozen over this year as the strong northern breezes [read Canadian air] have made waves and swells to keep the ice from forming across the 26 miles of the main body of the lake.
Enjoy your sailing.