Perhaps you’re going to Mozambique, Mauritius, the Seychelles, Thailand, the Red Sea (Egypt, Israel or Jordan for example), or some other equally exciting (and warm) destination.

Diving in Aqaba, Jordan, where I worked for a few months in 2008.

I would suggest you qualify as a diver here at home, for several reasons:

1. Diving courses contain a theory component, involving watching a dvd, self-study, classroom time with an instructor, and some quizzes and exams. Do you really want to be wasting your well-earned holiday hitting the books?
2. Resort courses are usually way more expensive than a locally-run course, because you’re a captive market and can’t really shop around when you’re on holiday.
3. You’ve paid a lot of money to book your holiday and you want to have the best possible experience. To do that, I suggest that you make sure you’re totally relaxed and at ease in the water. Some people take a few tries to get comfortable with the idea of breathing underwater, and I promise you’ll enjoy your holiday far more if you’ve already mastered diving, and you can concentrate on enjoying the sights while you’re away rather than taking the first nervous steps towards mastering a new skill.
4. When you start diving, it takes a few dives before you are fully relaxed and able to turn your attention away from fidgeting with your kit to the underwater world around you. Rather let me help you fine tune your buoyancy and kit configuration while you’re here, so that when you go on holiday you can confidently tell the dive centre, “I need a large BC, 8kg weight belt and size 9 booties please!” No surprises.
5. Conditions in the Cape are very different to what you’ll experience diving in warm tropical oceans. You might think this a reason not to learn to dive here, but experienced Cape Town divers will tell you that if you can dive here, you can dive anywhere. It only gets easier!

(This information also appears on my website, here.)