What are Wet-Mate connectors? A complete guide to subsea electrical connectivity

In subsea operations, maintaining reliable power and signal transmission is crucial for the functionality and safety of various underwater systems. This is where Wet-Mate connectors come into play. These specialized electrical connectors are designed to be connected and disconnected while submerged in water, often in the harshest of marine environments. 

Wet-Mate connectors are indispensable for the functioning of various underwater systems, ensuring continuous and efficient power supply, as well as signal transmission to vital subsea equipment. In this guide, we will delve into what Wet-Mate connectors are, how they work, the differences between Wet-Mate and dry-mate connectors, common use cases, and what to consider when selecting a connector for your subsea applications.

Wet-Mate connectors explained: What they are and why they matter

Wet-Mate connectors are electrical connectors specifically engineered to function in underwater environments. Unlike standard connectors, Wet-Mate connectors are designed to be connected and disconnected in submerged conditions without compromising their functionality. This makes them essential for operations where traditional, dry connections would be impractical or impossible.

These connectors are used to connect various subsea devices and deep-sea systems, such as remotely operated vehicles (ROVs), autonomous underwater vehicles (AUVs), Unmanned Surface Vehicles (USVs), subsea sensors, and power systems on offshore platforms. Whether it's for energy transfer or signal transmission, Wet-Mate connectors ensure that the connection remains intact and fully functional even in deep-sea conditions, where pressure, temperature, and saltwater corrosion could damage standard connectors. 

The main advantage of Wet-Mate connectors is their ability to establish a safe, reliable connection underwater. They are constructed with advanced sealing mechanisms and corrosion-resistant materials, making them capable of operating under the harshest conditions. Without these specialized connectors, many subsea operations would be impossible, as conventional connectors cannot perform under such extreme conditions.

How do Wet-Mate connectors work in submerged environments?

Wet-Mate connectors rely on several advanced design features to work effectively in submerged environments. The fundamental principle behind their operation is the ability to maintain a reliable electrical connection, even when immersed in water. To achieve this, Wet-Mate connectors are built with the following components and features:

Sealing Mechanisms

Wet-Mate connectors are equipped with sealing structures that prevent water from entering the connector, which would otherwise compromise electrical connections. These seals are typically made from materials such as rubber, elastomers, or polymers that create watertight barriers. This ensures that electrical integrity is maintained even when the connector is submerged.

Corrosion-resistant materials

The materials used in Wet-Mate connectors must be resistant to corrosion, as they will be exposed to salty seawater for extended periods. Metals like stainless steel or specialized alloys are commonly used in the construction of these connectors to withstand corrosion. Additionally, materials such as Polyether Ether Ketone (PEEK) are also favored for their non-magnetic properties and chemical resistance.

Pressure resistance

Wet-Mate connectors are engineered to withstand extreme depths without deforming or malfunctioning. These connectors are pressure-rated for reliable performance from several hundred meters to 1,000 meters, with specialized deep-sea connectors exceeding 6,000 meters in depth.

Electrical integrity

The electrical contacts inside the connector are designed to maintain strong connections even when submerged. These contacts are made from materials that are both conductive and resistant to corrosion, ensuring that the flow of electricity remains stable, even in harsh underwater environments.

Wet-Mate vs Dry-Mate: What’s the difference and when to use each?

The key difference between Wet-Mate and dry-mate connectors lies in the conditions under which they can be connected and disconnected.

Wet-Mate connectors

Wet-Mate connectors, as the name suggests, are designed for underwater applications and can be connected or disconnected while submerged. They are ideal for systems requiring frequent underwater mating, such as ROVs, AUVs, and subsea sensors. Most Wet-Mate connectors are made with rubber, offering flexibility and effective sealing. It’s important to note that Wet-Mate connectors can be safely plugged in and unplugged underwater when the power is turned off.

Dry-Mate connectors

In contrast, dry-mate connectors are designed for use in dry conditions. They require the connection to be made before submerging the equipment in water. Once mated, the connection remains secure during operation. Most dry-mate connectors are made with corrosion-resistant metals. Similar to Wet-Mate connectors, Dry-Mate connectors can only be safely plugged in and unplugged underwater when the power is turned off.

Wet-Mate connectors are particularly useful when operations involve the need to frequently connect and disconnect equipment underwater. This is common in ROVs, AUVs, and underwater exploration missions, where changing tasks or systems require constant plugging and unplugging of electrical connections. Dry-mate connectors, on the other hand, are more suited for stationary equipment that does not require frequent disconnections or reconnections underwater.

Where underwater electrical connectors are commonly used

Wet-Mate connectors are crucial in various industries where reliable underwater electrical connections are necessary. These connectors are commonly used in:

Underwater vehicles and robotics

These underwater vehicles such as Remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) rely heavily on Wet-Mate connectors to maintain a connection to the surface, enabling control and power transmission, as well as sending back valuable data from deep-sea environments.

Offshore energy systems

Offshore wind, oil, and gas platforms depend on Wet-Mate connectors to transfer power and signals between submerged equipment, such as power distribution hubs, control units, Monitoring and Sensor Systems.

Subsea sensors and instruments

Many underwater sensors and instruments require electrical connections to gather data from the ocean floor. Wet-Mate connectors ensure these instruments remain powered and communicate with surface systems during their operation.

Defence and marine science equipment

Wet-Mate connectors are used in military and research applications where reliable underwater communication and power supply are required. These can include sonar systems, marine research devices, and military underwater equipment.

How are Wet-Mate Connectors made?

Wet-Mate Connectors’ ability to maintain a reliable, watertight seal in harsh marine environments relies on a precise and carefully controlled manufacturing process:

1. Mold Design & Manufacturing

To meet the demands of marine engineering and other underwater applications, mold design and manufacturing process for underwater connectors requires the use of high-hardness mold, along with precision machining to ensure accurate detailing. A well-designed mold ensures excellent sealing performance, enabling connector’s housing and internal structure to achieve high precision and reliability.

2. Injection Molding

Next is the injection molding process, where the connector housing is formed. Molten rubber is injected into a precise mold that encapsulates the connector structure. For Wet-Mate connectors, the mold design is especially critical — it determines the final waterproof sealing performance.

3. Contact Plating

Once the connector bodies are formed, they are sent for electroplating, which adds contacts with a layer of metal (such as gold) to enhance corrosion resistance and conductivity. However, during this step, subtle issues like scratches, pinholes, or uneven coatings can occur, especially on the complex angular surfaces of waterproof connectors.

4. Assembly

Install O-rings and apply heat-shrink tubing to ensure proper sealing of the connection. Solder the contacts to the wires as part of the assembly process.

5. Deep-Sea Pressure Testing

What sets DWTEK apart is its use of pressure chamber testing, which simulates deep-sea conditions. This ensures quality that each Wet-Mate connector can withstand the extreme pressure found in subsea applications without leakage.

What to look for when selecting a Wet-Mate connector

Selecting the right Wet-Mate connector for your subsea operation is essential for ensuring reliable performance. Here are the key factors to consider:

Consideration 1: Connector type and contact option

Different applications may require different types of connectors, including circular, micro, or rectangular shapes. The number of contacts (contact options) is also an important consideration, depending on whether the connector needs to transmit signals, power, or both.

Consideration 2: Depth/Pressure rating

The connector should be rated for the maximum depth and pressure it will encounter. Choosing a connector with an adequate depth rating is critical to prevent failure due to underwater pressure.

Consideration 3: Signal vs Power transmission

Wet-Mate connectors can be designed for signal transmission, power transmission, or a combination of both. There are two main types of Wet-Mate connectors: 

• Purely electrical connectors: for power only
• Ethernet connectors: handle both power and signal transmission

Consideration 4: Material durability

Ensure that the connector is made from materials resistant to corrosion, pressure, and fatigue. For example, it is common to use PEEK (poly-ether-ether-ketone) on ships because PEEK is non-magnetic. Non-magnetic materials may be necessary for certain applications, especially in environments sensitive to magnetic interference.

Consideration 5: Industry standards compliance

The selected connector should meet industry standards such as RoHS or Reach compliance to ensure its durability and reliability in subsea operations.

Not sure what type of Wet-Mate connector you need? Or do you require a customized solution tailored to your specific subsea application? DWTEK offers bespoke connector designs to meet unique operational requirements — ensuring performance, safety, and long-term reliability under the sea. Please reach out to learn more!

Why choose DWTEK as your trusted Wet-Mate connector provider

DWTEK stands out as the first Taiwanese company dedicated to underwater engineering, with a proven track record in underwater connector development. The company not only designs and manufactures its own Wet-Mate connectors but also integrates them into its proprietary ROVs and subsea equipments - demonstrating their reliability through real-world missions.

DWTEK also offers connector customization service, including:

• Diverse Connector Configurations (Standard, Double-ended and Multi-ended Types): DWTEK provides a wide range of connector types, such as micro circular, standard circular, low profile, low profile micro, high power, power battery, Ethernet, diving, rubber molded, penetrator right angle, penetrator straight, and both wet and dry metal shell variants. This variety allows clients to select connectors that best fit their system layouts and operational needs.Custom double-ended and multi-ended connector solutions are also available, allowing for optimized integration within complex subsea system architectures.

• Custom Contact Option (Pins) Configurations: Tailored pin arrangements are available to accommodate specific signal transmission requirements, ensuring optimal performance and compatibility with existing systems.

• Material Selection: A customer can choose their own connector materials that offer resistance to high pressure and corrosion, enhancing durability and longevity in harsh underwater environments.

• Cable Assembly Customization: DWTEK offers customized cable assembly solutions, including cable arrays, client-specified cable routing, and tailored configurations. Each assembly is engineered for durability, deep-sea waterproof integrity, and reliable performance in demanding subsea environments.

With a focus on quality, durability and support, DWTEK is your dependable partner for long-term performance and responsive technical assistance.

Wet-Mate Connector FAQs

Q1. How deep can Wet-Mate connectors operate?

Wet-Mate connectors are available in various depth ratings and can typically operate at depths up to 6,000 meters, depending on their design and pressure resistance.

Q2. How long do Wet-Mate connectors last underwater?

With proper maintenance, DWTEK’s connectors are engineered for long-term use. Each unit is rigorously tested for voltage, current, insulation resistance, and pressure rating to ensure durability.

Making the right connection in subsea operations

In the high-stakes world of subsea operations, reliability isn’t optional—it’s mission-critical. Choosing the right Wet-Mate connector can mean the difference between seamless performance and costly downtime. These specialized connectors ensure robust communication and power transmission even under extreme pressure, corrosion, and unpredictable underwater conditions.

DWTEK not only manufactures a wide array of underwater connectors but also offers fully customizable solutions engineered to meet the unique challenges of your subsea systems. Each product is backed by rigorous testing, real-world application, and a commitment to long-term performance.

Whether you're operating ROVs, deploying offshore energy infrastructure, or conducting scientific research, DWTEK is your trusted partner for underwater connectivity. Contact us today and discover how our engineered solutions can keep your mission moving—deep below the surface.