Buoyancy control is a "touchy-feely skill" It is only achieved with a lot of diving. Do you think you can manage that in your locale, with it's severe weather? A couple of pointers: RELAX-your constant breathing will do more to throw your buoyancy off than anything else. RELAX-breath normally, not like there is no guarentee of your next breath. RELAX-do not fight the water. RELAX- are you getting the picture?
Ensure that your weighting is proper, then move on to positioning your weight on your tank and body so that your body position is virtually horizontal. This positioning will allow the best way to approach coral, fish, and other un-suspecting subjects for your camera. ( It is also the most efficient way to move in the water column) PARCTICE PRACTICE PRACTICE!!!!
