Yeah, I purchase an SMB when I got the Nitrox tank. It's not something we use locally. Have watched a few videos on how to carry and deploy them. I will practice this when I get to Blue Hole in April. Although I have not taken an UW Nav class yet, I have experience in orienteering. I will be brushing up on this skill soon. My son took an UW Nav class and not one time did they take him out to a large park and work with him prior to the UW qualifying dive. I coming to the conclusion that some classes are just a way to generate revenue for dive shops. I took my son out and laid out a course for him using tent pegs. After a few attempts he got where he was finding the pegs pretty often. One thing a learned from watching videos on UW Nav is to intentionally take a heading the will just miss desired position either left or right. Then when you have traveled the distance you know which way to turn in order to find your target. That was helpful.
We use a combination of natural and compass navigation alot down here along with an understanding of the geography of the reef or wreck. Underwater Nav is definitely a course which can be fantastic or worthless depending upon the quality of the instructor. I've never taken it myself but years of navigating Midwest quarries, lots of shipwrecks, and ocean shore diving and drift diving here in SEFL have honed those skills pretty well.
One dive that will use ALL of your nav skills and hone them well is Blue Heron Bridge. You will use your compass, the flow of the current as it changes at high tide, the angle of light, the shadows from various things topside, the sounds from boats and shore, and your knowledge of the geography of the area every single dive! Then dive it at night and it's even more challenging! It's a shallow site so technically you can typically pop to the surface, get your bearings, and drop back down. But I take it as a challenge to never do that! I've only had to do that once that I recall and that time alone pissed me off!
Sounds like you will be in good shape to enjoy your time diving here!