As you go deeper beneath the sea surface, water pressure increases. This can disrupt the stability of your set-up which can cause the camera to drift to one direction. In return, you may get blurry or out-of-frame shots. Use this balance to always have the Olympus PT-030 underwater housing on an evel keel to get clear images with the SP-310, SP-320, and SP-350 all the time. This item is also adjustable depending on the water's buoyancy.