From where Issuma is (was) docked, getting out of the marina involves a 90 degree turn shortly after leaving the dock. This turn is quite difficult to do in ice, as it is hard to apply a lot of power in turning. Having two propellers helps a lot, but it still took an hour of back and forth and chopping at the ice with boathooks etc from the bow, to make this turn. The auxiliary rudder was removed (you can see it on the dock), as I wanted to try breaking the ice in reverse as well as forward, and felt that might put too much of a strain on it. Issuma can only break very thin ice in reverse, as otherwise the ice is too close to the propellers (which would be very expensive to have to fix or replace). I think the main rudder (steel, controlled by hydraulics) is strong enough to back down into ice (slowly) without straining it.
A Slow Turn