Marine connectors are designed to provide reliable connectivity in shipboard or underwater environments, and are essential for the design of unmanned vehicles such as UUVs (unmanned underwater vehicles), AUVs (autonomous underwater vehicles), ROVs (remotely operated vehicles) and USVs (unmanned surface vessels).
Marine connectors can be used to help transfer power and digital, RF or optical, signals from one subsystem to another, and connect external devices such as cameras, sonar or other sensors.
Marine and subsea environments can cause galvanic corrosion due to saltwater spray, humidity and moisture, and thus connectivity issues may arise. Underwater connectors designed to operate in these environments may therefore have parts made from such materials as stainless steel, tin-plated copper, nickel-plated brass, and marine bronze.
Marine-grade electrical connectors may also be rated to different levels of environmental protection, such as IP68 and IP69, depending on the level of moisture or depth of water they are able to reliably function in. In addition to ingress protection, shock and vibration are other environmental factors that may affect marine connectors. These may arise due to engines, the effect of wind and waves, or bumping into docks and obstacles.
Connectors suitable for use in maritime and underwater environments can be grouped into three marine connector types according to the conditions under which interconnects can be made:
Wet-mate connectors can be connected and disconnected while submerged, making them ideal for situations where a human diver may have to swap out equipment without returning it to the surface.
Splash-mate connectors can be connected while the faces are wet but not submerged.
Dry-mate marine connectors must be connected in air before being submerged.
Marine cable connectors for deep-sea applications will have to withstand large pressures. A common technology used in deep-sea connectors is PBOF (Pressure-Balanced Oil Filled), in which the part of the cable and connector assembly carrying the electric wires or fiber optic lines, is filled with oil to allow the pressure between the interior and the outside seawater to equalize whilst also resisting corrosion.