John, We have just spent 6 weeks on a site, Jodl Camping a little further along the lake than Camping Terrassen Ossiach which is a large quite commercial site.
Camping Jodl is Family run and is excellent we have been there 7 years running. Has just 90 pitches all with a view of the wonderful See. Facitlities excellent too. To see more about this site go onto my website http://www.dvthompson.webs.com/ About joys of caravanning in Europe. The web site for Jodl is www.camping-jodl.at Good Luck are you going out of season as this is an ACSI card site and only 15 euros a night then. You can book a pitch without having to pay deposit, it is advisable as this area is very popular.