chrisch
Contributor
Wow... .it must be as cold as a Yeti's butt at that depth and a 300m dive requires a very long exposure and considerable logistical support. Nothing about doing this as a shore dive makes much sense.
R..
The lake shelves steeply. Although there are a few boats there nearly all diving is from the shore. I don't think there are any specialist dive support vessels and so you would need to bring something in by road.
Although I have never been below 50m in the lake I can see that (with a scooter) you could get very deep very quick. To the north of the lake is more shallow (Diving Areas Garda Trentino - Lake Garda)