Even if they aren't interested in learning how to dive before their vacation, they might be interested in learning to snorkel or in having their kids learn. Similar to a skier who goes on a skiing vacation once a year. These people spend a great deal of money on travel, and travel is the biggest market share in the diving industry. The other end of this equation is the dive resort. What needs to occur is for resorts to have a program that starts right around the time the dive boat leaves.
Parents can drop off their kids in order to get some diving in.
Kids will be learning to snorkel, making beach crafts, having swimming races, etc. in a supervised environment. There should also be a progression of skills through the week, with a ratings system that is industry wide. In skiing, a skier rates himself on a scale of 1-10, with specific skills being involved in each rating. For kids, this becomes invaluable in evaluating their specific skills. Another area in which skiing has advanced beyond diving is in the private lesson.