Until the 1850s, 'open' sea bathing, in the open sea, was not generally considered acceptable. It was, however, permitted within large timber structures as protection from predatory marine life and away from public view. The first formal St Kilda Sea Baths were opened in 1860 and provided separate sections for men and women. Women were protected from the sight of men bathing because men frequently bathed naked. Sea bathing was popular as it was considered to have health benefits. Throughout the 19th century there were as many as six different sea baths operating along the St Kilda shore.