don Francisco
Contributor
The problem with the concept of a balanced rig, or trying to balance one is that both the weights and displacements change with depth and time. Your tanks will get lighter as you breathe them down, and your displacement will decrease with depth as your wetsuit compresses.
You need sufficient ballast for the "lightest" situation; shallow depth and empty tank at the end of the dive. Unless you plan to pick up additional weights on the bottom during the dive, you'll be overweighted at the beginning of the dive when you reach maximum depth with an almost full tank .
The difference between the beginning bouyancy and ending bouyancy is what you're compensating with the bouyancy compensator, because no fixed combination of rig and ballast can be neutral throughout the dive.
You need sufficient ballast for the "lightest" situation; shallow depth and empty tank at the end of the dive. Unless you plan to pick up additional weights on the bottom during the dive, you'll be overweighted at the beginning of the dive when you reach maximum depth with an almost full tank .
The difference between the beginning bouyancy and ending bouyancy is what you're compensating with the bouyancy compensator, because no fixed combination of rig and ballast can be neutral throughout the dive.