Safety Warning

Well, it looks serene enough, and the expanse of water might be inviting.  But I don ‘t think I would want to venture into it, whether or not the signs were there.
This expanse of water is a reservoir which supplies water for large parts of Southampton and Hampshire, and is such is man-made in the relics of old quarry and gravel pit workings.
Which means that this, and the adjoining lakes, are best left to the wildlife and birds which habit the area.  The lakes themselves are very deep and are often topped with toxic algae.
I often visit them because in themselves they provide an area of natural beauty, as well as an interesting place to walk for exercise. It’s a favourite walking area for dog owners too.
 
But I wouldn’t even contemplate the idea of swimming or diving here whether or not there was a sign forbidding either.