I wont be sailing at Altona - a northerly is an offshore wind... You could sail at Williamstown, behind the break water -> gives a short speed run, although I'm not a fan of the sharp rocks and eel's, ie you really need booties.

Green Point in Brighton is good for the northerlies -> it is cross-shore; if you break something, you will eventually come in downwind at Sandringham (unless you sail too far out). Alternatively, Rye is good in a northerly but I suspect that may be a bit far for you.

If the southerly change comes in today, either Elwood or St Kilda is a good choice.

Cherry Lake...yeah...it seems they should change its name for "Muddy Lake" or something like that. I was there once and I was afraid - its looks so horribly dirty, especially coz of all that heavy industry around...do you think is that water safe ?
(I mean chemical / biological contamination ?

HaHa ! - I was there (Altona Beach) this afternoon. This time wind forecast was accurate, there was SW-S wind, 14-18 knots I recon, plenty kites and only 3 windsurfers. But...this is pretty got spot ! Huuuge area to sail, very good and very close access to the water, grass to rig, free carpark, not bad really !
I am going to do it regularly, just need to improve water start :(

I'd probably give cherry lake a miss - they regularly have fish kills, and they are the ones that are reported! Same goes for Koroit creek plus raw sewage and industrial waste that escapes. Some pretty hardcore industry in the area, petrochemical, plastics etc... Rox where you described all the big jellys - thats where koroit creek spews into the bay. The bastards can sting too. Some of the fisho's reckon its because of the drought, not enough fresh water flushing down the estuary. or they could be mutants!

Surprisingly though the water clarity is usually far better than st kilda....

I sail at williamstown beach as much as I can (when I'm not injured) - great in a w, sw,se and e wind. The rocks can be a problem, particularly the reef that runs off the groin - it has claimed heaps of fins. If you break something you could washed on the rocks - safer to sail at altona. At willy watch for swimmers that do laps in between the bouys, they swim in all weather.

see you out there when I'm fit...