I am father of 2 boys age 16 and 17 and I want to introduce them to scuba diving for the 1st time. We can all swim quite well and have snorkeled many times before. We are vacationing in Aruba over Easter Break from high school. From what organization should we learn to SCUBA? Are there discounts offered in any coupon books or.... We plan to do this early in the week and then possibly later if/because we enjoyed it so much. Signed, on a budget...