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What are the pros and cons of ordering wet-pluggable connectors? Can I mate and unmate a cable with this connector underwater?

Wet-pluggable (also referred to as wet-mateable or MCBH) connectors, an option on all of our underwater instruments, may be mated in wet conditions (click here for a photo comparison). Their pins do not need to be dried before mating. By design, water on the connector pins is forced out as the connector is mated. However, they must not be mated or un-mated while submerged. Wet-pluggable connectors have a non-conducting guide pin to assist pin alignment & require less force to mate, making them easier to mate reliably under dark or cold conditions, compared to our Impulse XSG/RMG connectors (XSG/RMG connectors may not seal well in extreme cold; we recommend connecting cables in warm ship’s lab rather than on deck for these conditions). Like XSG/RMG connectors, wet-pluggables need proper lubrication & require care during use to avoid trapping water in sockets.

Wet-pluggable connectors do add additional cost to the instrument. The increase in price is dependent on the number of pins on each connector, and the number of connectors on your instrument. When should you consider configuring your instrument with wet-pluggable connectors? Consider the following guidelines:

  • Internal recording with a profiling CTD (for example, SBE 9plus with 17plus V2, SBE 19plus V2, SBE 25plus) — Connecting/disconnecting frequently to the CTD is typical for these systems, for uploading of the internally recorded data. Wet-pluggable connectors are recommended for these applications.
  • Autonomous water sampling (SBE 32 Carousel with AFM or 17plus V2, or SBE 55 ECO Water Sampler) and internal recording with a profiling CTD — Connecting/disconnecting to the underwater electronics is required after every cast, to re-arm the electronics for autonomous water sampling. Connecting/disconnecting is often done on deck, where the connectors are exposed to splashing and rain; wet-pluggable connectors are strongly recommended for these applications.
  • Real-time data acquisition with a profiling CTD (for example, SBE 9plus with 11plus Deck Unit, SBE 19plus V2 with PDIM and SBE 33 or 36 Deck Unit, SBE 25plus with PDIM and SBE 33 or 36 Deck Unit) — The underwater units in these systems are plugged into the sea cable, and typically are disconnected infrequently. Wet-pluggable connectors are not as important for this application.
  • Moored instruments
    — If data upload after recovery will occur on deck to allow for quick redeployment, wet-pluggable connectors are recommended. 
    — If data upload after recovery will occur in a lab, wet-pluggable connectors are not as important for this application.

Note: Prior to 2005, the wet-pluggable connectors available had a rubber-to-metal seal that could break down with prolonged use (3 - 5 years); seal breakdown will lead to instrument flooding. Sea-Bird recommended frequent inspection of the connectors for damage. We also discouraged the use of wet-pluggable connectors for moored deployments, because they cannot be inspected during a prolonged deployment. 
From 2005 to 2007, Sea-Bird transitioned to the WB (water block) type of wet-pluggable connectors. WB connectors have a water block that minimizes the possibility of instrument flooding; we do not discourage the use of these types of connectors for moored deployments. If you have wet-pluggable connectors on your instrument and are unsure of which type you have, contact Sea-Bird.