Mark
I have used this Thigh Pocket from Diverite on my warm water trips.
Dive Rite Pockets for Slates, Weights, Masks/Utilities, and More
It does the job but I recently changed to having a few pockets glued on.
You can also look at Oxycheq. They have a strap on and a glue pocket. Look at X and g pockets here:
pockets
John