Even if you get an answer of 'yes', you should dig deeper:
Check if there is a 'fee' or additional taxes you must pay. I think there is a 16% fee of some kind.
Be sure there is not a cap (maximum) on the credit that you can spend for diving. For example, I've read you can use credits at the spa, but no more than $270 worth. After that, you have to pay full price.
Check to see if those paying with credits have different rules or less availability. They may limit the number of 'spots' for credit users, and then fill them quickly. "Sorry, it is full, unless you want to pay with cash".
Check to see if there are different booking rules for credit users, such as 'at least 48 hour advanced booking only' or 'no more than two reservations at a time allowed'.
Check the rate structure, and see if there is a huge cash discount. It would suck if dives were $150 per trip, but cash customers get a 33% discount.
There are lots of way to reduce the value of the credits.
Please understand, I don't have any experience or knowledge of the actual situation. I do think that these are possible areas of frustration if not completely researched before booking.
