nasty said...
Get yourself over to west coast Ireland on a good forecast if you can. You'll struggle to find better wave sailing anywhere when it's firing
Actually forgot to include Ireland as well as the UK:
Ireland:The place to be is the Dingle Peninsula. Works in almost any wind direction and when the swell gets to big you can always find a protected bay with flat water. While there make sure you pop into the Greenroom for a Guinness or six but make sure you brush up on your Aussie folk songs if you don't want to embarrass yourself.
The entire west coast of Ireland has a number of great surfing locations... if you do the trip make sure you visit Gallway... they have some of Europe's best Oysters (if you like Oysters that is).
Cornwall:Plenty of quality wave sailing in Cornwall. The golf stream runs past here so water is usually quite warm. Be prepared for a lot of driving though. If you head for Cornwall it's best to check with one of the local windsurf stores for where to go. There are a number of UK wave sailing events happening thought summer... it's a good bet that they are held at a beach with good conditions.
Scotland:Great country side and friendly people... and don't forget the best single malts in the world. It's worth a trip just for the 150 km Whiskey trail.
As far as wave sailing goes try Thurso on the northern tip of Scotland. It's pretty cold weather by Oz standards but gets some massive swells. There is a really impressive photo in the "Storm Riders Guide to Europe" of a 45 foot ground swell hitting a reef just off Thurso. Pre jaws that was the scariest thing I had ever seen.
The Island of Tiree is another popular spot but it's a bit of a pain to get to. Although the wind and waves can be great there.
I also sailed Loch Ness while I was there... didn't see the monster but the sailing was similar to Lake Garda. The westerly winds funnel down the Loch which can make for some fun high wind sailing. But the wind direction needs to be pretty spot on for it to work.
Overall though I would give the UK and Ireland a miss (I know I'll be stoned for this comment) as there are too many other much better options in Europe.
FYI, still nothing beats West OZ! Perfect combo of friendly people, warm weather, consistent summer winds...