The Coast Guard cutter Hawser was breaking ice between North River Pier 99 and Pier i early Monday morning as temperatures hovered around 11 farenheit. This section of the estuary generally remains navigable without human intervention, with the steady barge traffic and ebb and flow of the tide sufficient to keep the channel clear, but this is an exceptional winter. The 65-foot small harbor tug is the only Coast Guard icebreaker working New York Harbor this morning I believe, with both of the local 140-footers busy up north (Penobscot Bay is working north from Poughkeepsie and Sturgeon Bay is off Newburgh) and the other 65-footers Wire and Line and the buoy keeper Katherine Walker not showing up on AIS. After making a loop as far north as West 72nd Street, Hawser spent some time around the Manhattan Cruise Terminal where Norwegian Breakaway arrived this morning and then headed for the Upper Bay.