Trim weight pockets allow a diver to distribute small amounts of weight to different areas of his buoyancy compensator (BC), which helps to adjust his balance and swimming position. For example, a diver who moves a few pounds of weight into upper shoulder trim weight pockets will have more head-down position than he did without the weights present. Trim weight pockets are generally located on a BC's upper back, shoulders, or tank bands.
Trim weight pockets do not allow for a quick release of weights in an emergency. Divers generally distribute only a few pounds of their weight into trim weight pockets, and leave the majority of their weight on a weight belt or in an integrated weight system. For example, a diver who normally uses sixteen pounds of weight may put four pounds into his buoyancy compensator's trim weight pockets, and leave the remaining twelve pounds on his weight belt. In an emergency, releasing the belt and its twelve pounds will still cause the diver to float.
