Well everyone, I made it back from the Bahamas! I ended up carrying the ankle weights in my carry-on along with my comp and reg. I went through with no problems!! AND my checked luggage was not searched!
Now.... On the way back, I decided not to carry the extra 3.5lbs of lead on board with me and put the weights in my checked luggage. Wouldn't you know, it was opened and rifled through. I guess 2 long lead tubes probably would set off a few alarms under x-ray...lol. Nothing was damaged or missing.
As for the trimming capabilities of adding one ankle weight around the neck of the tank, PERFECT!
I dove once w/o it and was still "foot heavy" and then clipped one weight around the neck, and wha-la perfectly balanced! Now I can hang fins down to check out a ship wreck/wall or I can hang head down to peek under a coral head.