3) An idea of the bottom of the lake?    Any idea what's happening down there?

3) The bottom of the lake is   (where we have seen it)   made up of little dunes like this.
Here at a depth of 60 m (197 ft), these little humps have an average diameter of 20-25 cm (7-10 in).


At a depth of 140 m (460 ft): Here the little humps have an average diameter of around 40-50 cm (16-20 in).
(here under the "spar" of the brig).                               To pictures of the brig: Eanc02.html

At a depth of 310 m (1017 ft): Here, they are about 40 cm (16 in) in diameter
(here in front of the stem of SS Aigle II/Simplon, to give you an idea.)   To pictures of SS AII/S: ENvap.html

(Here AT THE BOW of SS Aigle II/Simplon, sunk in 1935: even after 70 years, they are still easily visible).

---

Very different!          But also very slow...
In the bed of a river, at a depth of 100 m (328 ft), the sides of a canyon

(Back to "Lake Geneva"...)