weight difference AL80/Steel

[spectrum]

Isn't just the difference in bouyancy characteristics that you can adjust? I mean all things being equal, if an al80 is +4lbs at the end of a dive and a steel whatever is -1, then I can remove 5lbs from my weight belt. It is that simple, is it not?

Nope

Weight and bouyancy are two different properties.

Bouyancy refers to an objects tendency to rise or fall in a water column.

Weight is mass and is what you feel when you are walking in your rig. it is also the mass you are moving through the water. The bouyancy takes over in the water with respect to the efect of gravity.

The weight you wear to compensate for excess bouyancy is extra weight load. The extra weight required for structural integrity of an aluminum cylinder is more additional weight load.

In terms of correcting your rig with the cylinder change you are correct with the 5 pound figure. The dynamic effect goes beyond just moving weight. You will come out lighter. Remember that bouyancy and weight are not the same thing.

Pete