I've kayaked the area south of the swansea caravan park lakeside and it isn't very deep - shallow for quite a while + it looks like it might be a bit protected from wind swell by the islands to the Sth. There were quite a few kites out there over the weekend.
Anyone sailed there? What's the likelihood of it being an ok flatwater speed spot in a S?
Very shallow myself and Steve Walsh tried it 3 years ago on speed boards in sw. It was flat enough but shallow with an outer reeff you can not sail over. Maybe now people have smaller fins it's worth a try again.
if you have a kayak why don't you paddle over it , when you get to the shallowest bit jump out and suss it out , if its knee deep it will be fine for a 18cm weed speed , maybe even a 21cm, if your using a slalom fin be careful
Us kiter get there a lot out of the Co-op in a SW or big southerly or northerly, but generally only on twin tips with 5cm fins 
occasionally some go there on surfboards.
I reckon you guys could get in there occasionally when the tide is high like it is atm
byron is correct that there is a shallower bank along the edge of the deeper section closer to Wangi, at a low tide this might only be about 15cm deep
