I don't feel safe unless I or someone else has posted stickers advertising that this is a single sex service under The Equality Act 2010, and defining "woman" as "adult human female" at the entrance of the women's pond, although these are generally fairly quickly removed. Even then, I don't feel completely safe, but safer.
Recently, while I was in the changing room shower after my swim, I saw through the large window, someone built like - although perhaps not too obviously - a man, get out of the pond. He behaved differently from women who go there - he lifted his arms euphorically, revealing swathes of pubic hair on either side of his costume crotch. He came into the shower, briefly showered under the cold shower without undressing. He noticed me looking uncomfortable in the next shower - my costume down to my waist - waiting for him to go so that I could take off my costume and proceed with my shower.
He could have used the cold shower outdoors - it seems coming into the indoor showers where women are naked was part of the experience he wished to complete. He could have used the mixed pond.
I felt that my safe space and privacy were violated.