How far will beaver swim under the ice

[Daslogster]

Looking for any trappers personal experience with beavers. A place I have been trapping for just over a year has a large lodge and dam (about 60' wide) damming an approx 2.5 acre pond on a piece of land I do not have access to. There is a small channel about 6' wide and 4' deep , 20' long, connecting it to a small maybe 1/2 acre pond that I have been trapping. The dam and lodge are about 200 yds away from the channel and last year I started setting in the channel under ice in the spring when the water started opening up around the edges of the pond and started getting beavers immediately. They have pretty well decimated the trees surrounding their lodge and swim into the pond I trap as there is still enough trees that I will be trying for a dozen out of the pond this year. How far can they swim under ice in search of food? They went about 100yds last year to my sets and I would like to start setting sooner this year but won't waste time until open water happens closer if I have to wait.