As I said, this depends on where you're flying. In the mountains, you
better be *very* obsessive about it, or you'll find yourself in a very
uncomfortable situation sooner than you've expected. There are
"outlanding field directories" for the Alps, and I have the known
landing options marked on my map. Plus, in the Alps, we do our landing
options calculations with only half the nominal L/D ratio, which
translates to roughly 1:20 for a standard 15m glider. Believe me, even
with this conservative approach, it can get pretty uncomfortable when
you hit an unexpected downdraft.

Stefan

Good point Stefan. It does depend on your prospective. 99% of my
flying is in the heartland of the US where it is flat. I have some
experience in the mountains of New Mexico where all you have to do is
turn away from the rocks and there are strips and roads you can use in
the valleys. Those I marked on a map also. Sometimes, like you say,
you get sink that really gets your attention though. Many times out
there you see 10kt+ lift and sink that matches it.

I've traveled a bit in the Alps (not flown there yet) of France,
Italy, and Switzerland and can understand why you do what you do. Lots
of rocks there with narrow valleys between. I would think with all
the great scenery, it would be hard to keep your mind on the task at
hand.

Have a good one,

Don