Some time ago I published an article diving by day in this cave that is located 18 meters deep in Cabo de San Martín and that gets its name because inside there is a stone block with an image of a virgin (Virgen de los Desamparados).
It is a siphon-shaped cave and, although you do not need to be an advanced diver, you will have to be careful both when finning so as not to raise the mud on the bottom and to control buoyancy during the ascent through the siphon.
In this video you will be able to appreciate the absolute darkness of the sea at night, as well as the contrast of the colors illuminated with a flashlight in that same darkness.
You will also be able to appreciate how that same darkness provides absolute calm at times, but also overwhelms at certain moments (which you will notice in the breathing), for example when going up the siphon (almost at the end of the video), since when looking towards above (so as not to hit yourself when entering through the siphon hole), the second main stage (the regulator) offers much less air so, if you don't know it or are not used to it, that lack of air can be very oppressive.
Video recorded with a GoPro Hero 8.
Photographs are screenshots taken from my videos.