Like ummmm, what good are they?
I maxed my sub out pretty soon after it was introduced and in that entire time - six months maybe? - have NEVER received ONE CRYSTAL and the rewards now seem to be all paltry diamond amounts. One Reward was ALL diamonds (26)
It gets worse, in the last fifteen dives, TEN have only been to 700 metres with the best being 1200!
I sent a message to SC - waste of time I know - and their reply was something like "oh don't worry, it's quite normal. Keep diving and the big rewards will come to you!"
And how long do I have to wait for these BIG REWARDS?
Game just keeps getting nerfed more and more seems to me!