19 year old Soldier looking to follow some dreams

Hello, I am in the United States Army as an 11B. I've always wanted to live in a beautiful tropical location, my fondest memory as a kid was snorkeling on the 7 mile beach in the Grand Cayman, and I grew up in Palm Bay Florida.
I get out of the Army in June 2015, my dream is to leave the army, pack my bags, and move to The Virgin Islands, The Keys, America Samoa, or somewhere similar.
I want to be A scuba instructor or something related. I have a 5stardivers over here in El Paso TExas, and I plan to get certified while in the Army, since they offer weekend classes. My questions are

1. How possible is it to mvoe to one of those locations and be successful? I dont have alot to my name, and my family doesnt either.
2. If I get certified in Scuba in El Paso, is that valid for other locations? What other certifications would I need? Night Diving, Boat Diving? Etc
3. Please give me any info or advice you can.

Thank you for your time.

Garlaaand;
Go to: VImovingcenter.com  It is a blog/forum that almost everyone who lives in the VI is on. They will be most helpful to answer your questions, give you tips and tell you about licensing, etc.
When you go to the site, click on the message board and then on relocating and that will take you right to the forum and you can find and read previous questions and answers or pose one yourself. It's a great forum for answers.  Good luck.