If you have ever wanted to try scuba diving, the Caribbean is a great place to try it out. There are a lot of schools that will train you so that you are able to do a dive and see what you think of it. After you can decide if it is worth it for you to take further training or not although that may depend on where you live if it will be worthwhile.
For those that are already certified, there is no reason you cannot go out with someone who is a beginner if you want to. There are a lot of different locations out there that you can check out and they are easy to get to for a new person to scuba diving. This activity could be a great one for a family to do together as they will have memories to last and discuss later.
When you are scuba diving, you see fish and other underwater creatures that you might not see when snorkeling as you are going deeper down. A new person may not go too far down as they need to learn how to equalize and just move around with all the equipment on their back.