1.  Are there age requirements?

Kids over the age of 10 are catered for by the Junior Open Water Diver Certification.  At age 15, the Junior certification upgrades to a regular Open Water Diver certification. No upper age limits but your ovrall heath is a factor.  For example, obese coffin dodgers would need to satisfy the Instructor that they won't pass away during the course - deaths aren't good for business.

2.  Will I have time to get fully certified while on vacation?

The PADI qualification which will enable you to dive anywhere in the world in the PADI Open Water Diver  course - the the most popular dive course in the world! The PADI Open Water Diver course can be split into five or six sessions over as little as three days to a much as six weeks.  Dive centres in holiday spots usually offer the Open Water course as a four day intensive course.  Note that this is a beginners course, if you become hooked on diving you'll find yourself taking intermediate and advanced level courses.

3.  Classroom study: What does it cover?

The main focus of the classroom portion of the Open Water Diver course is on the effects of pressure on your body. As you dive deeper, the pressure on your body increases. This changes the pressure of air your regulator delivers and, especially, the amount of nitrogen absorbed into your blood.  It is vital you understand the implications of these effects.

4.  Pool practice: What does it cover?

This is where the fun begins.  Taking your first breaths underwater on a  scuba regulator is a memorable experience. The pool sessions are where where you begin mastering basic practical skills: breathing from a regulator, safe descent and ascent procedures, proper buoyancy and so on. Yeah, of course to look like a bit of a dick wearing full scuba equipment in a 5 foot deep pool - but you'll be out of there in a day.

5.  How are the open water dives different?

In terms of skills, they aren't. The main difference is that now you are in open water and therefore can't stand up, grab the poolside etc.  As in the pool, the purpose of the training dives is to allow your instructor to determine if you have mastered the skills you need to be a certified diver.

6.  Can I dive on holiday without getting certified?

Yes, you can. These experiences go by different names according to where you are: "Introduction to Scuba" or "Scuba Diver Course" are two of the most common. The activity usually consists of a morning pool session during which you are introduced to the equipment and practice several essential skills. Then you are taken on a open water guided shallow dive, closely supervised by your instructor. These courses are a quick, safe and  inexpensive way to see if scuba diving is for you. 

7.  Are the instructors qualified?

Yes, you will find that the Instructors and Assistant Instructors working on Koh Chang all have a great deal of practical diving experience in addition to their paper qualifications.  Diving is a very competitive business and cutting costs by hiring unskilled instructors is a sure fire way to go out of business. 

Read this article on identifying a good instructor.