You are doing the right thing by questioning your training path. I'd suggest taking it one step farther, question your ultimate goal. Why do you want to be an instructor? Do you enjoy teaching? Are you particularly good at teaching? Do you have lots of patience? We have too many instructors who love diving, but aren't very good at teaching. If you think that might be you at a future time, you might consider a different path. If you have lots of patience and enjoy teaching others, you should work towards your goal.
If you just finished your OW course, it's time you got some experience before taking another class. There are those who disagree with me, but in my opinion, you should get in a minimum of 25 dives after certification before taking the advanced class. I'd also shop around for a course that offers more than 5 dives and includes in depth academics.
Most rescue courses are pretty good, but make sure the instructor doesn't cut corners.
My recommendation would be to learn CPR and First Aid from an EMT or Paramedic who is qualified to teach for American Red Cross or a similar organization. You'll get a much better class than from most dive instructors.
Before you go beyond this point in your training you need to evaluate your philosophy on dive training, compare it to the philosophies followed by various agencies and decide which is the best match for you. Regardless of which agency you choose, you'll be unhappy if your philosophies don't mesh well. I'd be unhappy teaching for most agencies, but I have found one I can be happy with, you need to choose wisely as well.
There are two major philosophies on teaching diving. Only you can decide which philosophy is right for you.
Philosophy 1.
Diving is fun and easy. It is possible to make the course easy as well if we eliminate skills that might possibly frighten anyone on their first day of class. If too many skills are included it results in task loading which will interfere with a student learning necessary tasks and make them an unsafe diver.
Philosophy 2.
Diving is fun and easy. It is possible to make the course easy as well if we begin with simple skills and allow plenty of practice time on each skill. Once a simple skill is mastered, other elements are added to the skill allowing plenty of time to practice each element. When those added elements are mastered, still more elements are added in the same manner. By approaching skill development in this manner we are able to teach quite complex skills in a manner that makes it easy for students. Skills that might seem frightening to a student on the first day of class are a logical and easy progression by the time those skills are presented in class. This gives a student confidence and the ability to solve problems without panic.
Some agencies follow philosophy 1, others follow philosophy 2. There are some which fall somewhere in between. There are more than 2 agencies. Most divers are PADI certified. PADI is the largest agency by far. PADI follows viewpoint 1. NAUI & YMCA follow viewpoint 2.
Once you've settled on which agency you wish to continue with, schedule your divemaster training. Most divemaster training is a joke. The only good divemaster classes are those in which you work an internship in addition to academics. You need to learn basic boat handling, including lines and knots as part of your training and practice. You need to learn to handle groups from other agencies and viewpoints. Divemaster is one of the most important steps in the path to instructor and one of the most difficult. Take your time to master divemaster skills before moving on. Once you've completed your divemaster training and have experience working as a DM, you won't need anyone's guideance on how or when to proceed from there.
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