Well I use google earth to check out posssilbe spots lach, but using images from the archives of the travels of captain cook and the bounty is asking a bit much 
i reckon that could be the You Yangs in the background, so somewhere down the west coast of the bay, maybe point cook?
heres an angle with water in the foreground
www.flickr.com/photos/87791108@N00/5391228257/
I found this www.flickr.com/photos/87791108@N00/176149199/
an uncanny likeness(mountains obscured by cloud?)
The way I came across this is I heard that there is an exhibition of von Guerard's
paintings at the national gallery of Victoria which very accurately depict well known Victorian landscapes in the mid 1800's .It is interesting that there are people swimming in the painting despite public bathing being banned at beaches until the Early 20th century .An interesting snub to the rediculous rules of the day (kind of like not being allowed to be kiting 1/2km out to sea from a flagged area )
Not sure about the name of the spot, but it has something in common with lots of kite flat water spots: the swimmers are loitering right in the spot we want to bust tricks! 
Then again, at least it looks like there are no parking dramas for this spot
The painting (by Eugene von Guerard), was painted on-site on a paper sheet. It previously had the title "Mount Macedon From a Point Between St Kilda and Brighton, 1857". It is Macedon Ranges in the background. St Kilda Pier's earliest form was built in 1853 and is not visible either is the original large headland that was origianlly at Point Ormond (later dug out), so this scene is likely to be somewhere between Point Ormond and St Kilda, quite possible right near the kite beach at St Kilda.
BTW there is a retrospective of von Guerard's work on at the NGV right now, it has views ocean views of Dromana, Cape Schanck and Phillip Island but mainly inland scenes.
Actually, seeing as you got me going. The artist Walter Withers had friends who owned Point Henry in the 1880-90's, he painted several works on the beach there. If you are kite there you might be interested in seeing this:
www.artgallery.nsw.gov.au/collection/works/8558/
Mid-tide, seemingly Westerly wind!
