Anyone who has been scuba diving at CN I need some help!

The course they provide allows you to scuba dive at their resort presumably (please correct me if I'm wrong).
Does going scuba diving cost any $?
Do they have night scuba diving? We did night snorkeling last time we were there a few weeks ago and it was awesome, totally worth the $35. Wondering if they do night scuba and how much the additional charge is?

Thanks for the help!