Even "tropical" destinations where the rent aluminum tanks, I would recommend SS plate. It will offset the positive buoyancy of the empty tank.
I use an aluminum plate locally, but I dive my own steel tanks. If I end up having to use an aluminum, I put weight in the pockets affixed to my cam bands or even thread hard weights on them.
I use an aluminum plate locally, but I dive my own steel tanks. If I end up having to use an aluminum, I put weight in the pockets affixed to my cam bands or even thread hard weights on them.