Ben Flewett wrote:

If you do enough cross country wave flying you will,
sooner of later, get trapped above cloud.

I do not agree. Know the weather. Allow yourself enough time to build
experience. Keep sharp on the development of the weather. Never, never,
never fly above a lenticularis. Keep your föhn gap in sight. Be sure
your glider can penetrate against the wind. And if in doubt, don't go.
But you knew all this before.

If you insist that getting trapped by cloud can't be avoided, then, by
all means, install at least a needle and get some training on it. You
simply can't control a slippery glass glider in cloud without a gyro.

Stefan