Buoyancy and Depth Control

The weight of the vehicle in water is offset by the air inside the hull and the float block on the top of the ROV. Ballast weights can be added or removed to achieve the desired buoyancy. Buoyancy can be affected by fresh or salt water and the buoyancy of any accessories that might be mounted on the ROV.

The depth of the Pro 4 Ultra is controlled by a vertical thruster. For the thruster to operate efficiently, the buoyancy of the ROV should be near neutral. This can be accomplished by adding or removing ballast weights that are stored in the skid pods on the bottom of the ROV. The skid pods are hinged at the rear and can be opened by unhooking the O-ring at the front. Turn the ROV over on its top to add or remove ballast. The ballast weights can be positioned within the skid pods to trim the ROV level, or pitched slightly up or down.

The procedures to adjust the buoyancy are described in the Dive Operations section of the Quick Start Instructions.

Product Evolution

The ballast weight system has been revised. The current system uses push buttons to open the skid pods and stainless steel weights with a square cross section. Earlier versions used brass weights with a round cross section, and the pods were held closed by O-ring bands.

The older round weights will fit in the new pods, but the newer square weights will not fit in older pods.