Lots of great discussion here! I have to jump in and add my 2 cents as someone who is an avid cold water diver but also has lots of warm water experience. I did most of my training in cold water, from OW through to OWSI. But I also dive at least 50-80 dives per year down south, so I know that there are challenges to warm water diving as well.
Here`s my view: I wholeheartedly believe that when starting out as a diver, one should learn to dive in cold water if they plan on diving under those conditions at a later point because it is a lot easier to learn in warm water and a lot harder to adapt to cold later on.
Having said that... no, I don`t agree that as a dive professional you are necessarily better off doing your training in cold water, especially if you are already an accomplished cold water diver. I believe you need to be well-rounded. So, if you plan on teaching and think it is likely you may end up in cold water areas, you had better get some cold water experience as a diver before you take your first students out on a course. Conversely, if you are a cold water diver but plan on teaching down south, you will need some warm water experience as a diver.
I for one would have a hard time having a DM on my boat who I knew was not comfortable in cold water. But they don`t have to have gained this experience in their professional course.
What is more important when selecting a dive professional training program are the following (at least in my books):
- The quality of instruction and the reputation of the dive centre. Ask around. Find out what people are saying that about that dive centre. Find out how their students are perceived and find out how their dive professionals are perceived.
- The amount of hands-on experience with real students and customers you will get during your training. My personal view is that the minimum requirements set out by PADI are just that - minimums. The more experience you get, the better DM you`ll be in the end.
-Don`t try to cram it all into a week or two!
My issue typically with warm water professional development centres is the duration of their programs, not the temperature of the water. This is often out of necessity because people drop in on their vacation to complete the course, but I think we sometimes get confused by the issues with DMs and instructors who learned in just 1 week as opposed the fact that they did it in warm water.
I realise that as someone from a cold water centre, this may seem to be the wrong answer. But in truth we believe the DMs and Instructors who learn with us come for the quality of the teaching, not the temperature of the water. I would encourage you not to let that be your deciding factor.
Best of luck to you wherever you end up! The very fact that you are putting so much thought in to your selection of a dive centre to learn with bodes well for your success.