In this report no 121, the Winter Navigation Research Board presents the results of research project ChannelWidening, Full scale trials of channel widening with IB Polaris. The capability of icebreaker Polaris to widen the broken ice channel using propeller flow was systemically investigated. The width of the channel behind the icebreaker was investigated at different icebreaker advancing speeds and different stern thruster toe-in angles. The channel width was determined by analyzing bird-view drone videos.The test outcomes indicate that Polaris can efficiently create channel with width of 32 m by applying toe-in angles of 30 – 45 degrees when going ahead with a relatively high speed of 5 knots. The toe-in angles could also be used to widen a previously opened own channel. According to the test outcomes, the speed as high as 8 knots could be maintained while widening a previously broken channel, which is valuable for an assisting icebreaker.