Hey Jamie,
I'm from Port Fairy and the windsurfers regularly sail @ the golf course (mills) on a W, WSW... Otherwise if wind is more Southerly they will be further up the bay toward Port Fairy...
On a W - NE go to the loch (lake at port fairy down from Golf Course...) Also known as Port Fairy Airport... Look for the Windsock, setup there....
Cleanest wind on a N - NE, can be gusty on W - NW
They don't really sail killarney much but is good for flat water if you say infront of the reefs...
Hope that helps....
Hopefully they wont mind me telling you!

Cheers