Sistema Ponderosa, Cenote Jardin of Eden
Downstream line started next to the cavern line that went to Rainbow cenote. Max depth was 51 and average 30ft. The line did a few sharp turns and ups and downs. Halocline was shallower than 30ft. and quite well defined, i.e. there was definite separation of fresh and salt water. Due to halocline being shallow and cave going up and down we spend the whole dive moving from fresh to salt and back, creating some neat photo opportunities like the first picture below that shows my buddy dropping towards me through the halocline.
Other highlight was the cenote on the left less than 100 ft on the way in and the rays of light penetrating through the cracks. It was possible to drop down below halocline and look up towards the rays of light right through it. All that made for some pretty interesting shots with halocline in the background - note how blurry the rays of light are in some of the shots.
Upstream dive was an exercise of ultimate photographic frustrations. The halocline stayed right above the line very close to the ceiling and was fairy well defined, thus making it possible for us to stay in the salt layer (below) and look up to see the river of fresh water flowing above us back towards the entrance, complete with ripples effects. After the last hurricane, the flow was stronger than I remembered and that was a fascinating show to watch but very frustrating trying to photograph it as camera refused to see what our eyes could see so easily... We dove this cave on Xmas day, I took some Xmas shots in the cavern.