I made a transit with a learning sailor who had just bought a new handheld GPS.
It was a lower priced model with a map but not a true chartplotter. He wanted
to see The Rigolets, the outlet of Lake Pontchartrain, so he wouldn't be
intimidated should he ever do it himself.
As we made turn after turn along the route, I noticed he wasn't setting any
waypoints in his GPS. I mentioned it and he said he didn't need to because all
the marks were in the pre-loaded database in the GPS. I suggested to him that
it might be a good idea to have waypoints set in the middle of the channels
where he wanted to turn rather than using the fixed marks that lined the
channel. He thought about it and then the light came on.
On another occasion, I helped a friend bring his new boat home from across the
lake. It had a nice Raymarine charplotter. Imagine his amazement when, as we
motored down the middle of Mandeville Harbor, the symbol for the boat on his
chartplotter went through the middle of the seawall on our port side. What if
the visibility had been zero and we were totally relying on the chartplotter?
I have a waypoint set a hundred yards or so off the entrance. I can arrive at
the mark then feel my way into the harbor entrance in low visibility once I
have visual contact with the lights or seawalls.
I have two fixed mount GPS's and 1 handheld (kept in a waterproof pouch with
the batteries removed). The fixed mounted GPS's are at the helmstation and
navstation and are routed through a switch so that one or the other is
interfaced with the instruments and autosteerer.
Anyway, relative to the subject line, ALL the waypoints in my GPS's are
OBSERVED, That is, I took the boat to the spot where I wanted the waypoint and
hit the "Mark" button on the GPS unit. If I'm not comfortable with it, I've
been known to swing the boat around and go back and re-mark it. I always
delete the other one.
If I'm going somewhere new, I may enter a waypoint from a chart but once I
reach that point, I may adjust it according to where I really want it when I
observe the conditions at the waypoint.
I'm always amazed at how many boaters use government marks, bridges, etc. for
waypoints. For instance, I set a waypoint on either side of a bridge opening.
I don't want to use the center of the opening. Never know when you're going to
arrive in a thick fog or other adverse conditions. Government marks, buoys,
bridges, etc. are things to be avoided, not to be used for waypoints.
My mid-channel waypoints are set such that I am well away from points, shoals,
etc. If I need more than one waypoint to navigate safely around a bend, I set
them. I can always cut the corner in good visibility.
So, the next time you enter a waypoint in your GPS, ask yourself "Is this
REALLY where I want my boat to be in zero visibility?"
Still, having waypoints you are comfortable with doesn't relieve you from
maintaining a diligent watch or totally, completely trusting them. Remember,
aids to navigation and navigational aids are used to help you, the boatowner,
skipper, to properly navigate.
I still have paper charts on board and, although I don't have a sextant, I do
know how to determine my position by triangulation using a hand held compass
and charted objects on the shore and waterways. The paper charts are always
out for reference every time I make a long passage.
Dennis C.
Touche' 35-1 #83
Mandeville, LA
_______________________________________________
This List is provided by the C&C Photo Album
http://www.cncphotoalbum.com
CnC-List@cnc-list.com
