Borg:
I usually do my diving at Lake Lanier when I can't get to Fla. So I will work on my skills when I'm up there soon. It's definitely 7mm wetsuit time now. I 'm wanting to get a drysuit after the 1st of the year.
A popular dive for us in AOW is Peak Performance Bouyancy, and we usually encourage students to do the additional PPB dive for specialty certification. If that turns out to be the case for you AOW, you can prepare by making certain you are properly weighted for you 7mm. The usual exercises are swimming through a line of hula hoops, anchored at different levels off the bottom. For the deep dive, your problem may be a multiplication exercise, or some other cognitive activity, that you do on the surface for time, then repeat U/W for time. The biggest issue for deep dives, inland, in winter, is the water temperature. I have had AOW divers bail simply because they were waiting to descend to depth to work with the instructor, and it was too cold and too dark, even at 50 feet. If Lanier is where you will be doing it, you may want to get some idea of the temperatures and level of thermoclines in advance, to know what to expect.
mauigal:
Also on the navigation dives, your instructor should do compass work with the class before getting in the water to do your actual dives. Say doing a square pattern. 4 ~ 90 degree turns, making sure all you can see is the compass. Maybe out and back on a straight line.
For navigation for AOW we do both. Have the students buddy up, and do an out an back on a particular compass heading and back on the reciprocal. We also have them calibrate their kick cycles to distance e.g. set up a 100ft line, have them fin at a normal rate from start to finish, to determine individually what their kick cycles / unit distance is. Then we have them as a buddy team complete a square, with 90 degree turns as Mauigal notes. The first time around, one buddy is compass person, the other is kick person, then we switch roles for another round.