cala tarida, has an interesting rock with loads of fish around it.
again cala conta, but i saw a man nearly hit by a boat there so made me worried as its not roped off.
the rocks at cala bass (behind the banana boats), its almost like a plunge pool and some interesting fishes.
playden bossa beach where it meets figurettes, theres a mini harbour near the jetty, pretty good, on the seward side theres a underwater bridge type thing for you to try and swim through. i saw an octopus here 2 years ago
i think best one imo is cala tarrida, as its loads of stuff in a small area.