WetLink Cable Splice Kit User Guide


The WetLink Cable Splice Kit enables quick and easy connection of two cable ends without the use of potting compounds, molds, or curing time. The resulting splice is depth rated to 500 meters and can be submerged indefinitely, making it suitable for reliable connections in underwater applications. This guide will show you how to use the WetLink Cable Splice Kit.

Before You Start

The WetLink Cable Splice Kit is only compatible with M10 size WetLink Penetrators, M06 and M14 size WLPs are not currently supported. Each cable end must have an M10 WetLink Penetrator installed before using the splice kit. For instructions on how to install WetLink Penetrators, check out these guides:

WetLink Penetrator Assembly Guide
The WetLink Penetrator (WLP) is our next-generation solution for low-cost, high-pressure, high-reliability sealing of electrical cables. This guide will show you how to assemble a WetLink Penetrator.
How to Choose a WetLink Penetrator
Learn how to choose the right WLP size for your cable.
Cable Stripping
Learn how to properly strip cables for use with WetLink Penetrators!
If you need to repair or extend the cable on a Blue Robotics product and you’re not sure which cable to use, you can always find a link to the correct cable in each product’s technical details table.

Parts and Tools

You Will Need

You will also need:

  • Two cables with M10 WetLink Penetrators installed to splice
  • 2 x M10 bulkhead O-rings (included with WetLink Penetrator)
  • 2 x M10 penetrator nuts (included with WetLink Penetrator)
  • 2 mm Hex driver


1. Take the M10 bulkhead O-rings included with the WetLink Penetrators and apply a thin, even coat of the included Molykote 111 compound. Install an O-ring in the O-ring groove on the underside of each WetLink Penetrator.


2. Take one of the cables and feed the wires through one of the holes in the splice kit enclosure.


3. Hold the penetrator in the hole while you fasten a penetrator nut on the other side. Tighten the nut until finger-tight.


4. Use one M10 Bulkhead Wrench to hold the nut in place while you tighten the WetLink Penetrator using another M10 Bulkhead Wrench. Tighten the penetrator completely, if the penetrator cannot be loosened using your fingers, it is tight enough. If using a torque wrench, the installation torque is 3.5 Nm.

A 16 mm wrench can also be used to tighten the penetrator on the outside of the enclosure but most wrenches are too large to fit inside the enclosure.

5. Repeat steps 2 through 4 for the other cable.

6. Once both penetrators are installed, make all wire connections inside the enclosure.

The wire connectors shown here are not included in the kit.

The wire connectors shown here are not included in the kit.

In this example we’re using Euro-style terminal blocks to make the connection, but you can use a solder splice and heat shrink, another type of terminal, or connectorized PCB depending on your cable.

7. Apply a thin, even coat of Molykote 111 to the splice kit lid O-ring and install it in the groove in the lid.


8. Apply a thin, even coat of Molykote 111 to the top of the inner surface of the splice kit enclosure.


9. Install the lid onto the enclosure and secure it using the lid screws and a 2 mm hex driver.


You now have a waterproof connection that is depth rated to 500 meters.



The WetLink Splice Kit has two built-in mounting features.

Mounting Screw Holes

Four 3.2 mm holes can be used to mount the splice kit to a surface using M3 screws (not included) or another type of screw.


The mounting hole pattern is shown below.

Zip Tie Grooves

Two grooves molded into the splice kit enclosure help to keep it in place when mounted using zip ties.



The WetLink Cable Splice Kit was designed to remain submerged indefinitely, eliminating the need for maintenance. If you frequently open and close the splice kit lid, you should check the lid O-ring for damage and relubricate both the O-ring and enclosure.

It is ok to use a tool to pry off the splice kit lid if it is difficult to open.


If the lid O-ring is damaged and needs to be replaced, the O-ring size is molded into the inside of the enclosure for easy reference. The O-ring size is 1.5 x 44 mm.


The Blue Robotics nylon O-ring pick can be used to help remove the O-ring without damaging the lid.



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