The 5% discount for Captain's Club members is available to every tier, matters not which tier. But.....you have to call them get the discount.
The online discount of 5% can be combined with the CC 5%, but again, you have to call to purchase. Also, there is a discount if you purchase 2 sessions.....one for you and one for your "other". They make wonderful mementos from the trip and the blowers do give you ample opportunity to do things yourself.
Very highly recommended, but as folk have mentioned, the slots fill up very quickly, so plan on attending the first demo.....right after sail away.