To secure the dive site in Switzerland, the following rules must be observed:

Dive flag

Law: entry and exit must be secured in each case with the flag "A" of the international flag regulation  (divers in the water): If the entry and exit are in different locations, then set up flags in both places.

Penalty: for not complying with the law may be subject to a fine. The fine can be up to CHF 200.-

So set up the dive flag and save money.