fnfalman
Contributor
Five of the seven responses you've gotten thus far are from instructors, so it might not be a representative sample of opinion on the subject.
Here's a response from a non-dive professional:
If the boat were to cancel the trip or cut short the trip because of rough condition, then yes, you should get a refund.
If the trip was dive-able and yourself, your son, or whomever, decided not to dive...well...it ain't the Captain's fault. Nor is it the charter's fault.
HOWEVER, in the interest of customer service, if I were the Captain or in charge of the charger, I might have done something for you and yours.