Most people float, which is great if you like to stay at the surface. However, scuba divers want to descend and need a weight system to help them offset this tendency to float. You want just enough weight to allow you to sink slowly. Having the right amount and proper distribution of weight allows you to fine-tune your buoyancy. Visit your PADI Dive Center or Resort to get advice about weight systems.
Choose your weight system based on your BCD.