Why some lakes have no electronic charts available.
Just as a point of interest to some, I'll offer a passing word of explanation why I think some lakes are not included on electronic charts:
I think one of the reasons resevoirs, at least, are often not included among the electronic charts, is that their shape and navigability change greatly with rising and falling water levels, even with islands appearing and disappearing in the process.
Consequently, VFR (Visual Flight Reference, as used in flight navigation) is the rule, with contour maps of the lake bottom being the most useful reference other than the simple full resevoir map itself.
Fortunately, the smaller nature of most resevoirs makes visual referemce possible. Really big ones, like Lake Powell, present more of a challenge.
The contour map would be an invaluable tool in such circumstances.
To effectively electronically maps such resevoirs, the chartplotter would have to integrate a lake contour map with a lake level input to calculate the current shape of the lake, etc,
I like to photograph lake structures a low water levels for future reference, particularly those with fishing potential.
Does anyone have an electronic chart of Lake Powell? Does it allow for water level differences?
Joe.