Jade, Gold and Silver, yes. Each one was harder to find, though the more observant players would surely get them without much difficulty.
Following the water tunnel, we reached a series of doors that we had to open to raise the motorboat and be able to return to the outer channels, but to do this we had to find two switches hidden nearby that would give us access to the final part of the level.
To make matters worse, to continue, we had to eliminate another mercenary from Bartoli, who was hiding to surprise us. If we were not fast, we could die in the attempt, so always with the pistols in hand.
Where did you find both switches?