...for taking such trouble, Julie. I am really grateful for this detailed information. I can't imagine where I got the notion, but I seem to recall thinking it kind of odd that the women were expected to hide inside these wooden huts and in flannel swimming costumes, while the men swam without their clothes and not too far off.

Searching for a source I thought it might be in one of Henry's caricatures but I found none. Only this picture from his Austen info pages where the young lady looks positively drenched and not quite as refreshed as one would have hoped. The guides look to be fully clothed! Must have been unpleasant an unhealthy to move about in wet clothes on the beach and in the water while the bathers came and left.
I take it that a female swimmer needed one guide to help with her attire (like a maid) and one to manage the horse? And since the guide/attendant was male or female, even if Hurst and Louisa were on their own, a married couple would not have shared one machine? I wonder if children were ever allowed to partake?