Although swimming had been included in the first modern Olympics in Greece in 1896 where it had three events held in the bay off Piraeus it wasn’t until the 1904, St. Louis Olympics, that a programme we would recognise today was introduced. However the programme was limited to nine events and was only open to men and did not include butterfly.
At the start of the 20th century swimming, water polo, diving and artistic swimming or water ballet (synchro) were all gaining popularity and new pools were being built to cater for the swimmers and new leisure time that was becoming available.

The South of England Advertiser noted in for 3 February 1910 that “Policemen, especially those in coastal towns, are realising the important of swimming more and more” and it is noticeable that around this time many events included teams representing the police.
In Sussex, galas and other swimming events were attracting large crowds eager to see the swimming celebrities that were being reported regularly in the national press.

Outdoor pools began to be built at almost every seaside resort.

One of the largest was the St Leonards bathing pool that opened in 1933 with a spectator capacity of over 5,000.
The pool was 110 yards (approx. 100m) long and held a million gallons of water. To cope with the demand for swimming and diving the pool had a depths ranging from 2ft to 15ft (4.5m) under the diving stage.

Others followed with Brighton’s Black Rock Pool (now empty land next to Brighton Marina) opening in 1936 and Saltdean Lido opening in 1937.
Other Sussex history pages:
History of swimming in Sussex – in the beginning
Championships through the years