Last week I was in Sardinia to do some trimixedives and a cave dive.
Here are some pictures of the Bel Torrente cave. The water was in the salt part 25 degrees C and in the fresh water part only 15. The average depth of our 150 minute dive was 3.9m, with a maximum depth of 12m. So extremely shallow.
You enter from the sea and this time there was no current. It has an intense halocline, some stalactites and the water is extremely clear in the fresh water part.