Scuba Diving vs. Para-sailing?

That's like asking, "Which is better, apples or oranges?" I personally would have a more meaningful experience scuba diving but that is just my opinion.

Do you dream of being a bird, or on an alien world?

I've never been "para-sailing," or at least not as I understand it. But, I have made a few jumps. The glide down is something to be experienced, and is just a little less thrilling than the free fall part. You would be amazed at what you can see. Of course, you won't be a high on a para-sail, but it is still something.

A dive, with SCUBA, is more awesome to me. I'm not talking about snorkeling, but actually diving with full gear. It is like, as it has been said, being in an alien world. The fish, when used to people, just ignore you and go on, like you're not even there. The sea-scape is alien to what you see on land, even in the desert, and holds all kinds of mysteries (just don't touch or stick your hand into anything). You may even get lucky and see a shark or ray, which can be amazing in itself. You will never feel as small as you do when next to a whale shark.

If you have time, why not do both? Say, a day diving and a day sailing. Unless you have already passed a SCUBA course, you will probably not dive alone, and it shouldn't take too long to cover the basics.