They will provide a mask, fins, bcd and a regulator at no cost. At CN you can rent a wetsuit for $10 so it may be the same at CSA. CSA has a great dive staff. You'll have a fun time, especially if the new dive boat is in service. The rumor is the new boat arrives in April.
As stated, there is no additional cost except for the wet suit. But, if you have your own stuff, why not bring it. Maybe not the fins if weight or space is an issue, but there is nothing like your own mask or reg.