Freedivers use lead weights to reach the required depth as quickly as possible. These weights can be strung on a Beuchat Marseillaise belt or a belt with a quick release buckle, so that they can be released quickly and easily if necessary.
Another solution is a harness, offering better protection for the back and especially the lumbar region. Harnesses exist in strap versions or in the form of weighted neoprene vests; further weights can be added on the belt.
The weight of the ballast is calculated according to weight of the spearfisher, the thickness of the suit, the depth of the dive and the saltiness of the water. The thinner the suit and the shallower the water, the more weights are added. At the other extreme, freediving at depth requires fewer weights.