Narrow passages

Some of the inside passages of southeast Alaska are very narrow.  The Malaspina is about the largest ship that can traverse them.  Even then, they use fairly elaborate navigational aids to help the pilot keep the ship in the channel.  Even so, when going through particularly narrow spots, an experienced watchman is at the bow of the ship, in contact with the pilot.  He's watching and listening, looking for boats or anything else amiss.  Serious business this navigation.