Hi
Heres my two cents worth if its of any help. Like the others said, its a bit hard to give specific tips if we dont know where youre heading. Here are a few places that I know of. Dont be put off by German web sites, as previously mentioned most Swiss divers speak English.
Lakeside Camping Grounds in Northern & Southern Switzerland:
Lake Constance aka Boden See
There is a nice camping ground with beach area and swimming pools just at the eastern edge of Kreuzlingen on the Swiss side of the lake Constance. Kreuzlingen is the twin town of Germanys Constance. Water temperatures are good for swimmers during the summer. Obviously the later you go during the summer season, the warmer the water. Lake Constance is also a lovely area for cycling. I usually combine my cycling tour of the area with some time at the beach near the campground. The countryside is very pretty, and the cycling paths are well indicated and well maintained. Ive never dove there but I know that Lake Constance is a very deep lake +300 meters with caves, grottos, and findings from WWII. Due to unusually low waters last summer divers found an unexploded English bomb! The lake is huge and offers many dive spots, some of which are specially designed for them i.e. off limited to swimmers. The university town of Constance (on the German side) is very pretty. The pedestrian shopping zone within the old town is picturesque with it narrow streets and immaculately maintained buildings. It offers museums (Zeplin etc), theatre, restaurants etc. Tips its cheaper to dine and shop in Germany than in Switzerland.
If you are planning to fly to Switzerland and renting a camper I suggest looking into Ryan air
www.ryanair.com. They offer cheap flights (for as low as £5.99) to Friederichshafen by Lake Constance in Germany. From there you can take a short ferry across to Romanshorn on the Swiss side or simply drive around the lake. Alternatively, Easy Jet
www.easyjet.com offers flights to Zurich and Geneva.
The River Rhine
Just west of Lake Constance, between Switzerland and Germany. Ive never tried it, but some diving clubs go there every week, and claim that its interesting. It should make for a good drift dive, as the current can be pretty strong in some places. Some public areas for swimming are available. Cooler water than in the lake.
Lake Zurich
Lake Zurich as well as the neighbouring Obersee offer many public beaches for swimming, but no camping directly on the lake. Youll probably find camping within 30 - 45 minutes. I think there is something in the Sihlthal, which is just one valley south of the lake. Perhaps there is something on the Far eastern side of Ober See. I dont know. Most consider the best diving spot on Lake Zurich to be the one by the Au peninsula aka Au Halbinsel. Contact Bettina from Dive Academy in Horgen
www.diveacademy.ch If I remember correctly she speaks half decent English. She organises regular diving excursions there, as well as by her school in Horgen. Mind you she probably wont let you go with the regulars unless youve already done lake diving. She offers a course for first time lake diver for a cost of aprox SFr 80. The reason being is that people whove only gone scuba diving in clear waters of the tropics tend to panic once they go in fresh water and consequently they slow down the others, because the frequently have difficulty with adapting to differences in buoyancy, visibility and waters temps, and altitude. During a hot summer like last year surface swimming temperatures can reach up to 22C, but as little as 3C below at depth. A shock if youre not expecting it.
Lake Zug aka Zugger See
The lake is the favourite diving spot of friend of mine who dives several times a week all year round. The lake has public beaches for swimming, and I think a campground too. The lake is medium small but quite pretty as its surrounded by small mountains. The water temperature is nice for swimming in the summer. There is also the picturesque town of Zug, which also has a pretty old town offering shopping, and romantic dining possibilities by the lakeside. The town of Cham is near by as well. For that matter, Lucerne isnt too far either. Tauch Treff Zug
www.tauch-treff.ch is based in Zug and can probably offer you some guided tours of the lake.
Four Forest Lake aka Vierwaldstater See
A famous large lake with it tip at Lucerne. It has lovely dark aqua water. I used to go windsufing there (in Urner See) years ago. I sometimes see divers in this very deep and very cold lake. The water is cold even for swimmers, but some still go in to cool off from the summer heat. Since the lake is largely surrounded by steep mountains, its not easy to find a spot to set up your equipment etc. The one tiny spot I know on the picturesque Axenstrasse is usually taken by windsurfers. Parking is limited and thus very difficult to come by. There are no toilets or other facilities for swimmers. Youd have to check with local club for more specific info in the area.
Southern Switzerland Vale Verzasca & Laggo Maggiore
Vale Verzasca is just north of Laggo Maggiore. There is a good camping ground at the northern tip of the lake just a few kilometres before the town of Lucarno. . I often begin my cycling tours from there. Valle Verzasca is a popular valley well known for its dam (the one James Bond bungee jumped from in the film golden Eye) and its beautiful arched bridge. The bridge is a tourist attraction in its own right, and very popular spot for diving or jumping into the cold water below. Although the water is cold, its a popular swimming hole. In terms of scuba, its famous for its crystal clear waters and beautiful rock formations. Max dept only about 8-12m. Bettina of Dive Academy is organising a weekend excursion there in mid August. Many European dive operators organise weekend trips to Versasca, as its suppose to be the best river dive in Europe. Since the diving spot is a drive up the hill, most of the divers find lodging up the valley rather than drive back down the mountain to the lake even though the drive is not far. However if your missus is a non-diver it might be a better idea to make a long service interval and drive back down. There is a lot more to do near the lake than in the valley. Because of it beauty, Southern Ticino and specifically Laggo Maggiore a popular tourist area. It offers many public beaches and parks, and along with it many boats. The tourist towns of Locarno and Ascona, offer a bit of shopping, several restaurants and generally tons of festivals in the summer. The atmosphere is usually pretty good and very Italian.
Have fun planning your holiday.
Sylvie