For new readers... Waysbury is a diving training venue near to Heathrow in an old quarry. It is excellent for training.
From Joanne….
We were brave enough to dip in 4 degree water in Wraysbury on Sunday. We were rewarded with a stunning visibility. We could see the undisturbed "quarry-bed", with at least 6 wrecks in sight and we encountered gigantic fishes (some are more than a meter long). I believe, this is not the norm for Wraysbury in most people's memory, but it did happen.