Rich, I am pretty new to diving myself (@ 92) and it looks like you are just starting out... The biggest problem I have seen with new divers is they do not have the ability to properly control their buoyancy!!! They can't keep off the reef, they can't stay on the picture, trim is all over the place, they don't know how to back fin, they are up, down, left, right, sideways!!! They just do not have enough experience to work a camera well...
If your taking a wreck class then maybe you might want to focus on the class instead of worrying about your camera bobbing about. If your going to be penetrating then your not going to want it "just" tether to your harness your going to want it secured well... but I say this more as with common sense rather than actual experience doing wrecks. Maybe your only going to observe the wreck from above and from the sides but with less than 25 dives and heading down to 130' you may already have enough on your plate...
My advice (new guy to new guy) is to focus on your class while your down it the water. When you have time to play, work on your buoyancy and working the camera in the pool or lake. Granted, the lake maybe poor vis but it lets you work on taking pictures, both close up and with some distance...
Best to you...