This online document is a means of sharing the adventure of traveling on America's waterways with friends and family. Last Dance is continuing to take her crew to historical, natural, beautiful, and interesting places. Enjoy the ride.

Monday, August 29, 2016

Georgian Bay - Navigation


Navigation of the waters in Georgian Bay is sufficiently challenging to require full attention from skipper and crew.  Fortunately, Canada publishes sets of very accurate charts, though in an unusual format of long, skinny folded sheets where it seems north is never up.  The electronic charts above show Last Dance entering Potato Channel, one of the two passages between the end of the Trent Severn Canal and the beginning of the Georgian Bay.  Looking ahead of the boat the water looks wide.  Checking the chart shows that while the water is wide, the places where the water is deep are few.  On most charts, where the water is indicated in blue, it is shallow.  Where it is marked white, it is deeper.  In the zoomed in chart on the left, actual depths can be seen.  The asterisks scattered all though this view indicate rocks just under the surface.




To get through the middle section of the channel, a hard 90° turn to port, where marker cannot be seen, is required.  Then a short channel leads to a hard 90° turn to starboard, seen ahead in this image.




Not much room to squeeze a beamy boat through between this pair of markers, and boats do not make square turns well.  But, at least the Coast Guard has marked this channel.  North Channel has no marked channels.


Made it, although the momentum made the stern swing a bit wide on exit.  An interesting story happened in this channel a few years ago.  A Grand Banks was negotiating the channel, right in the middle of the markers, when it hit an underwater obstruction quite hard.  The boat's momentum pushed the boat over the obstruction and back into deep water with a damaged keel and bent props.  This happened early in the season.  The skipper called the Coast Guard to report the problem, which they promptly investigated.  A full sized van was found with a groove through the roof created by the keel of the Grand Banks.  Over the winter, someone had been ice fishing, the ice got thin and their van fell through.  One would have to carefully craft their words to convince the insurance company that you were in the channel when you damaged your boat hitting an automobile.


Another marker system used by the Canadian Coast Guard is to place red triangles and green squares on islands and land along side the channel.  Sometimes the land is a rock barely underwater.  One advantage of these markers is that they are permanent.  The floating markers have to be removed before winter sets in and the bay waters freeze, then reset the next spring.  In this photo, there are three of the large, permanent markers visible, 2 reds and one green.



In case you missed them, arrows have been drawn to indicate locations.  Heading north and west in the main channel of Georgian Bay, red markers are passed on the right (starboard) side of the boat, and green markers on the left (port) side of the boat.  This sometimes changes when taking a side channel.  A big reason to pay close attention to those paper charts.  This one is an easy one - just keep the reds on the right, green on the left, and pass through the middle of the water ahead.





Like this, right?



 Surveying the entire area ahead of the boat is important, even critical in this case.  Behind the rock on the left is a floating red marker.  The marked channel passes to the left of this marker.  The floating red should be on the right (starboard) side of the boat.  Boats with more than a 3' draft taking a straight route through this area find themselves hard aground.  So the answer to the question: "Like this, right?" is "Wrong!"




A more circuitous route is necessary to avoid finding underwater rocks.  In 2016, with water levels being higher due to heavy snow falls the two previous winters, some deeper draft boats might have gotten away with a mistake here.  In years with low water levels, even small boats would pay the price.


Another navigational aide is range markers, used in long, narrow channels to keep the boat aligned in the center of the channel.  Byng Inlet was a large shipping port and the range markers are large and obvious to guide ships through the deepest part of the channels and into the narrow inlet.  A short one is in front and a taller one in back.  These are very rare to have lights, almost all are just painted markers.  In this shot, the front marker is to the right, indicating that the boat is too far to the left.  A turn to the right (starboard) is needed to line the markers up.



Now, the boat is too far right and a correction to the left is required.  With no range marker and only a red and green markers in the water, a boat a long distance off can be pointing to the center of the two markers and be far off the channel to the right or left.



Since range markers are for long channels, they are far away.  You must know they are there and look for them - another reason to study the paper charts.  Binoculars are required.  The above two images, with the red-lighted range markers, were made with a long telephoto lens for illustration purposes.  This image contains the third set of range markers for Byng Inlet (there are multiple turns to get into the harbor and multiple sets of range markers).  Less of a telephoto was used in this image.  See the range markers ahead of the boat?  They are a bit to the right of center.  To let mariners know they are looking at a different set of markers, they are painted a different color and have that color light.  Yes, green might not be the best color for makers in the trees.

The navigational challenges are one of the factors that makes travel on the water interesting, and sometimes exciting.  The crew has to be watchful at all times, keeping an eye on the waters and the charts (paper and electronic) to ensure a safe passage.


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