Below is "then and now" comparison of the Huntington pool at the right of each image. The one on the left is from 1937. Google's measuring tool gives the current length of the pool as about 70ft (about 76ft to the semi-circle), which seems in keeping with the 78ft length of the adjacent tennis courts.
mil.library.ucsb.edu/GSV
The 1928 aerial is a lot more blurry, but the pool doesn't appear any larger. I was just beginning to think that the Huntington never had an Olympic-sized pool when I found the following information in Langham's own guide. The reason it doesn't show up in aerials is because it went under the Picture Bridge. I notice they've used the same picture that was found by
Noir_Noir. NB. The map is roughly upside-down. Highlighting is mine.
www.langhamhotels.com (PDF file)
Now we just need a view looking under the bridge!