excellent points made by g1138. I would suggest you get as much drysuit diving as you can, you can certainly get started in Canada, buy a shell drysuit and dive it anywhere you go in the world. Public safety diving is very different from recreational diving, but diving experience is a big plus.
I am a rescue worker and recruits that have scuba diving experience tend to handle confined spaces and smoke diving gear well. It appears that experience with a mask that restricts your field of vision and somewhat constrained breathing via apparatus contributes to better stress handling across the board.
If you can find a way to volunteer or assist in any way at a local hospital or rescue service while on your gap year, I would recommend this as well.
As for internships, I would suggest paying for your divemaster, as then you are the paying customer with the power of going elsewhere if you are not happy, and once you have your DM cert, doing the internship and perhaps getting some of your course price refunded. That way you have more controll over your own destiny.
