Ready to enter the water!!!

They are old friends, but they don't see each other often because of work. They are both divers and love getting into the water, no matter where it is, from a small pool to the Yacyretá reservoir itself, in the south of the country.
The most experienced of the two is José Aguapé, the river otter from Concepción, who is a member of the navy, a combat diver and, in his free time, an industrial diver. But with all that knowledge he has, he still loves to dive recreationally, which is easier for him.
On the other hand, Saiyuki is a water lover like José, with the peculiarity and perhaps advantage, that he collects a variety of new and old equipment, which he lends without any problem to José himself and to his friends, especially to Aramí, who poor thing doesn't have diving equipment.
Jose's invitation for this occasion is to dive while night falls, with the challenge of showing anyone that, in the absence of sunlight, the underwater hues change color, and it is a totally different world from that of the day. Even nocturnal animals appear, something that we would not see diving during the day.
You will rarely see Jose using his diving wing, yes, he certainly likes it, but he prefers, as he has always said, to dive with a harness and nothing more than that, but since in that part of the Paraná River there is almost no current, he enjoys using his wing in those places, since the current will not take him very far according to him.
Saiyuki, on the other hand, always with some vintage diving equipment, also with only a harness, and his beloved double-hose regulator and his usual oval mask...
Both prepare to enter the water, eager to see what curiosities there are down there!!!.

Tell me: Have you dived at the end of the day? And if it is purely nocturnal; what peculiarities did you observe down there???