Description
The Subsea M8 Rotary On/Off Switch offers a compact and reliable latching control solution for underwater systems where space is limited. Designed for manual operation inside watertight enclosures, it enables users to toggle circuits on and off without breaking the seal or exposing internal components. With its M8x1 body and anodized aluminum construction, the switch is depth-rated to 1,000 meters and ideal for use on compact underwater vehicles, pods, or instrumentation housings.
The switch provides clear two-position actuation with a firm rotational stop and mechanical positioning pin, preventing slippage during use or under vibration. It supports low-voltage signal control at up to 0.5A 125VAC or 0.3A 28VDC, making it well suited for command or trigger circuits. For high-power applications, the switch can be safely paired with the MOS Low-Side Switch Board, which offloads the switching load while maintaining isolation and reliability.
This M8 variant is especially useful in tight or weight-sensitive builds where a smaller interface is required. For applications demanding a more robust grip or extended reach, consider the larger Subsea M10 Rotary On/Off Switch, which features both standard and extended knob versions, and is available in aluminum or stainless steel to suit a wider range of environmental and mechanical needs.
Routine use in sediment-rich or saline water environments may result in slight rotational resistance over time due to mineral buildup. This can typically be resolved by rinsing the switch in warm water and gently rotating it to clear debris, ensuring continued performance over its rated service life.
Pair with High-Current MOSFET Control Board
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For switching high-power devices like lights or thrusters, these rotary switches can directly trigger the MOS Low-Side Switch Board, available in 15 A, 30 A, and 120 A versions.
MOS Low-Side Switch Board
A compact MOSFET-based control module for the negative (low) side of a DC circuit. Accepts logic-level input from any Blu-Sub rotary on/off switch. Choose from 15 A, 30 A, or 120 A versions depending on your system’s current requirements. Includes onboard fuse protection and optional shell.
Need a Larger Switch Option?
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For users requiring a larger form factor or more tactile control, the M10 version offers extended knobs and material choices for a more robust interface.
Subsea M10 Rotary On/Off Switch
A full-size rotary switch available in both aluminum and stainless steel versions, with standard and extended knob options. Ideal for applications where a larger grip or added mechanical presence is preferred.
Compatible Subsea Enclosure Options
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The Subsea M8 Rotary On/Off Switch integrates easily into Blu-Sub subsea enclosures using a standard M8 mounting hole. Each compatible enclosure supports proper sealing and manual operation at depth. Ensure the selected housing provides adequate bulkhead thickness and internal clearance for the M8 switch body.
Subsea Watertight Enclosure Box
Compact aluminum enclosure rated to 300 m. Custom drill an M8 mounting hole as needed for switch integration. Ideal for rotary switches, sensors, or signal indicators.
Subsea Enclosure Acrylic Tube
Transparent cast acrylic body rated to 250 m, compatible with Blu-Sub aluminum or acrylic end-caps. Select or modify end-caps with an M8 port for proper installation and sealing.
Subsea Enclosure Aluminum Tube
Rugged 1,000 m-rated enclosure. Use with aluminum or acrylic end-caps configured or drilled with an M8 mounting hole for reliable switch integration in deep-water control systems.
Compatible Installation Tool
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This product can be installed using the Universal M8/M10 Installation Wrench, a dedicated tool designed for Blu-Sub M8 and M10 bulkhead-style components such as penetrators, switches, sensors, and connector-style hardware.
Its compact dual-end design allows installation in tight or closely spaced layouts, while cable-pass slots allow the wrench to slide over pre-attached cables, enabling installation or servicing without disconnecting wiring.
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Technical Specifications
| Subsea M8 Rotary On/Off Switch | |
| Material | Aluminum |
| Appearance | Black Bulkhead, Red Knob |
| O-ring Size | Ø10 × 1.5 |
| O-ring Material | FKM75 Brown Fluorine Rubber |
| Performance Characteristics | |
| Maximum Rated Depth | 1,000 m / 3,280 ft |
| Design Lifetime | 3 years or 500 cycles to rated depth |
| Temperature Rating (air) | -25 ~ 60 °C / -13 ~ 140 °F |
| Temperature Rating (water) | -4 ~ 40 °C / 32 ~ 104 °F |
| Button Travel | ≈1.3 mm |
| Wire Length | ≈200 mm |
| Wire Colors | Blue, Green |
| Wire Specification | 24 AWG |
| Electrical Performance | 0.5 A 125 VAC / 0.3 A 28 VDC |
| Reset Mode | Not Self-resetting |
Mounting Hole Dimensions
| Recommended Size | M8 Switch |
|---|---|
| Recommended Bulkhead Through Hole Size (A) | Ø8.1 ± 0.1 |
| Hatch Cover Thickness (B) | 14 mm |
| Surface Range (C) | 17 mm |
After using the switch in murky waters for a while, I sense some resistance while rotating. Is this normal?
Yes, this is normal. Impurities or salt crystals might have entered small crevices. You can alleviate this by soaking the switch in warm water and rotating it several times to dislodge any impurities.
Can this switch handle high-current power sources?
No, you should employ MOS switches or relays to manage high voltage and high current power sources.
Will the knob come off due to severe vibration?
No, the knob has a pin for positive positioning.
Can you provide an electrical schematic for the switch?
No, it's a physical on-off switch, so it can be simply referred to as a switch.
Can this switch be used in shallow water or in the air?
Yes, it is suitable for usage in water depths ranging from 0 to 1000 meters, as well as in the air.
Will forcefully twisting the knob cause damage?
No, it has a pin for positive positioning, but it is not recommended to apply excessive force as it may damage the aluminum knob.
3D Model Viewer
Note: The 3D model shown above is for reference purposes only. It may include components, accessories, or alternate sizes not included with the product. For simplicity, only a single representative size is typically displayed when multiple versions exist. Please refer to the product Shipping Guide for detailed information on included contents and size-specific differences.
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