Connectors

Connectors are used to join a cable to a device such as an underwater vehicle, instrument or battery; or to join two cables together. They can be used for electrical conductors or optical fibers, or both. There are many types of underwater connectors, some can be mated when wet, others must be dry. Some of the common types are:
• Cable Glands —actually not a connector at all but a rubber grommet in a housing that seals around a cable. They are inexpensive and easy to install but are not reliable for long-term immersions or in dynamic situations where the cable will be subject to flexing.
• Rubber Molded —neoprene rubber connectors molded to cables or onto metal bulkhead posts use compression seals or o-rings seals molded in female sockets. There are several common styles. Some have a vent hole for purging water when wet mated. Advantages are inexpensive and deep depth ratings; however, rubber can degrade with long-term exposure to sunlight and certain chemicals. It is not available in high-contact counts.
• Epoxy —glass filled epoxy construction bulkhead connectors with rubber molded mating cable connector. Inexpensive but not good for applications where epoxy part is subject to shock or impact.
• Metal Shell —some utilize rubber molded connectors bonded to an outer metal shell for increased robustness. Other types utilize an insert in shell. Wide variety of configurations available, including high contact counts.
• Glass to Metal Seal —hermetic sealing of pins to glass puck makes for a very reliable pressure proof seal but at higher cost.
• Pressure-Balanced Oil-Filled (PBOF) connectors, typically can be wet mated at any depth, because they are pressure equalized.
Connectors that mount to a pressure housing are known as bulkhead connectors . They typically have one or more o-rings for sealing. BCR-type bulkhead connectors thread into a tapped hole or are retained in a thru hole by a nut and washer. FCR types have a flange that attaches with mounting screws or bolts. In-line connectors are installed on the end of the cable. They are often known as CCRs and CCPs, where R stands for receptacle (female sockets) and P stands for plug (male pins). Dummy connectors are used to keep contacts clean when connectors are unmated.
Fiber optic connectors are available in both dry mate and wet mate styles, as are hybrid connectors, which have electrical and optical contacts.