Here is an excerpt from their website. (see below) It says 24 hour cancelation. If they adverise that on their website and then screw a customer out of $140, I wouldn't use them again either. The only exception would have been if they told you 72 hours verbally when you booked it.
If they have new owners and a new policy and haven't updated their website with the new policy, then that's the new owners fault. Not the customers.
Sounds like to me that they have "double standards". (see below for their posted policy)
http://www.scuba-do.com/pricing.html
Pricing for Scuba-Do
Scuba-Do offers two daily half-day, four hour charters at 8am and 1pm. It is our pledge to not put more than 10 divers on board to avoid a crowded boat! (Even though we are USCG certified to carry 14 Divers)With that in mind, we have a firm 24 hour cancellation policy for dive charters and a 48 hour cancellation policy for Instruction and charters during holiday periods! We do not offer refunds for seasickness, or for unused dive equipment and tanks! We appreciate your cooperation when scheduling your dive charters!