I’m confused, did you mean this will be your first dive using
underwater photo equipment or this is your first dive using scuba or both ?
Either way using a camera underwater can be most challenging.
All those concerns about how I should best set up my camera to get the best possible
picture. F stop’s, shutter speed, strobe settings, white balance, filters, the list goes on
the more control you have over your camera equipment. Not to mention composition
and keeping your buoyancy. Taking good picture underwater is a art
which takes many hours of practice. Getting familiar with your equipment is just one
aspect which you’ll have to learn. If you’re a proficient diver you’ll learn much faster.
My recommendations is get familiar using your camera with the least amount of effort.
First using auto mode and slowly taking more control over your manual adjustments
later. Understanding why your pictures are not coming out the way you would like
them to look commands you to take manual control over your equipment. Understanding
the relationship between aperture, and shutter speeds, and correct exposure will give
you that control .
Marc