Bert Willing wrote:
Circling at 400ft while being able to land anywhere doesn't mean unsafe
operations by definition. I frequently start circling over a ridge at less
than half of this altitude. But not always.
Everything depends on experience (with that glider), current training level
(with that glider), personal daily fitness, wind conditions and lift
conditions.
And you have to put the question "is it safe" every single time - but then,
this does hold for every manoeuvre.
You just have to accept that sometimes the answer to this question is "no".

Experience is no panacea.

F1 - Francois De Klerk died in his Ventus 2cx. He entered a spin trying to save
a launch at 450". He was a national champion and one of the most experienced
contest pilots. Unfortunately he can't tell us whether it was disorientation,
turbulence, or wind shear that stalled him.

Unless the landing options are certain to include serious injury it must be
considered unwise to even think of trying to thermal under your safe spin
recovery altitude. It used to be with the draggy wodd and fabric jobs that
people generally got away with it low down, but a modern glass glider with
elliptical lift distribution departs violently into a spin and does not recover
in less than 500-600" (altitude loss after recovery is irrelevant)

So - my opinion is - the answer is always no, unless you have already put
yourself in the position where you are effectively already dead, and all the
possible outcomes are no worse. Personally I would prefer to avoid getting into
the situation in the first place...