AT WHAT point does a man undergoing a sex change become a woman? This was the question that got a few cossies in a knot at the McIver Ladies Baths in Coogee on a recent Sunday, when a man claiming he was having hormone therapy came to use the ocean pool.

The 20-metre pool is Australia's last remaining coastal baths for women and children only and is listed with the National Trust.

"Some swimmers went to complain to the surf lifesavers on the beach, someone else called the police" ... early morning swimmers at McIvers Ladies Baths in Coogee. Credit:Kate Geraghty

Built in 1886, the baths were run by the McIver family until 1922, when the Randwick and Coogee Ladies Swimming Club took over the lease, which it still operates today. This females-only club predates Bondi Icebergs.

At first glance nothing much has changed since the McIver family ran the pool, not even the 20¢ admission price, which is collected in a bucket at the gate by an honour system. Most mornings at sunrise a group of swimmers - many of them seniors - brave the swell for a few laps of freestyle or breaststroke.