We see those objects spinning slowly around above the wheelhouse on each end of the ferries, but don’t pay them much mind. Those things are the radar domes that sweep the area surrounding the ferry with a signal. That signal paints a scene on the screen of the radar as if looking down from above of all the objects that reflect a signal back to the the ferry. Fiberglass boats don’t reflect a good signal, so most small boats have a special radar reflector to enhance the signal. The idea is not to hit something returning a signal, be it land, another boat, or even a log.
I was once at the helm of a 72 foot classic yacht crossing the strait of Juan de Fuca at night headed south for Admiralty Inlet when I glanced at the radar and noticed something dead ahead of the boat. I made a slight course correction, then looked to starboard at the water in the lights from the salon and saw we were passing a huge log end-on. I shuddered at the imagined damage such a heavy log could do to a wooden boat at top speed and thanked King Neptune for the radar technology. Never had it occurred to me that a log would reflect a radar signal.
In the old days, navigating the islands in heavy fog, the skippers would holler through a megaphone and listen for an echo to return. If it didn’t, the way was clear in the fog, but if it did and quickly, the idea was to turn the wheel away from the sound as fast as possible! It’s amazing the surprising level of expertise they developed over years at figuring the echoes, the current, the tide, and the learned route to their destination. Like the old saying: Practice makes perfect.
Photo location: Shaw Island behind the ferry, Orcas Island to the left, Harney Channel in the fog.