The Subsea M10 Pressure Trigger Switch is a compact, normally open underwater switch that functions either as a manual momentary button or an automatic depth-activated trigger. It is available in two trigger depth versions: 2 Bar / 0.2 MPa (20 m) and 4 Bar / 0.4 MPa (40 m), allowing integration into underwater systems where pressure-based activation is required.
Below the pressure threshold, the switch acts as a momentary pushbutton—closing the circuit only while pressed. Once submerged beyond the pressure activation point, it switches to a closed state and remains ON as long as that depth is maintained. This makes it well-suited for triggering behaviors such as ROV/AUV dive confirmation, safety interlocks, or automatic control sequences at specific depths.
The switch can also be paired with the MOS Low-Side Switch Board to enable automatic high-current control based on pressure. Once the rated depth is reached, the switch conducts continuously, allowing the MOS board to power downstream devices. Manual pressing above the trigger depth will temporarily conduct, but since it does not latch, it is not suitable as a manual override for the MOS board.
Note: The 20 m and 40 m designations are approximate and depend on actual water density. Users must calibrate trigger depth through real-world testing, as variations in temperature, salinity, and altitude will affect hydrostatic pressure. For example, seawater (density ~1,025 kg/m³) exerts more pressure than freshwater (density ~1,000 kg/m³), meaning the actual trigger depth in freshwater may be slightly deeper than in seawater for the same pressure rating. The built-in pressure tolerance allows for an approximate error margin of a few meters, which should be factored into system design.
The red actuation cap includes an M3 threaded hole for attaching a custom trigger button or extension. The housing is CNC-machined from anodized aluminum and rated for operation down to 1,000 meters depth. The switch uses a 2-wire output (24 AWG blue and green leads) and supports up to 0.5 A at 125 V in signal-level applications. When handling high-current or high-voltage systems, it is recommended to interface the switch with an external relay or MOSFET circuit for safe operation.
This normally open pressure switch resets automatically when pressure is removed and is designed to be self-cleaning through motion. After long-term use in murky or saline water, rinse in warm fresh water and press the actuator several times to remove buildup.


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The Subsea Pressure Trigger Switch can be paired with the MOS Low-Side Switch Board in specific scenarios. Once the sensor reaches its rated trigger depth (e.g., approximately 20 m for the 2 Bar / 0.2 MPa variant), it automatically conducts, enabling the MOS board to activate downstream devices.
Above the trigger depth, the sensor acts as a momentary switch—pressing manually will conduct, and releasing will disconnect. However, because this manual press is not latched, it is not suitable for use as a manual override with the MOS board.

Subsea M10 Pressure Trigger Switch – Materials & Design | ||
Item | 2 Bar / 0.2 MPa (20m) | 4 Bar / 0.4 MPa (40m) |
Material | Aluminum | Aluminum |
Appearance | Red Button, Black Bulkhead | Red Button, Black Bulkhead |
O-ring Size | Ø12 × 1.5 | Ø12 × 1.5 |
O-ring Material | FKM75 Brown Fluorine Rubber | FKM75 Brown Fluorine Rubber |
Subsea M10 Pressure Trigger Switch – Performance Characteristics | ||
Characteristic | 2 Bar / 0.2 MPa (20m) | 4 Bar / 0.4 MPa (40m) |
Maximum Rated Depth | 1,000 meters / 3,280 ft | 1,000 meters / 3,280 ft |
Design Lifetime | 3 years or 500 cycles | 3 years or 500 cycles |
Temperature Rating (Air) | -25 ~ 60°C / -13 ~ 140°F | -25 ~ 60°C / -13 ~ 140°F |
Temperature Rating (Water) | -4 ~ 40°C / 32 ~ 104°F | -4 ~ 40°C / 32 ~ 104°F |
Button Suspended Load | 20 N | 40 N |
Trigger Depth | 0.2 MPa (self-calibrating) | 0.4 MPa (self-calibrating) |
Wire Length | ≈200 mm | ≈200 mm |
Wire Colors | Blue, Green | Blue, Green |
Wire Specification | 24AWG | 24AWG |
Electrical Performance | 0.5A 125V max | 0.5A 125V max |
Reset Mode | Momentary, Self-resetting | Momentary, Self-resetting |

Recommended Size | Subsea M10 Pressure Trigger Switch (2 Bar / 0.2 MPa / 20 m and 4 Bar / 0.4 MPa / 40 m) |
---|---|
Recommended Bulkhead Through Hole Size (A) | Ø10.1 ± 0.1 |
Hatch Cover Thickness (B) | 13 mm |
Surface Range (C) | 20 mm |

After using it in murky waters for a while, I feel some resistance when pressing the button. 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 pressing the button repeatedly 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.
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 1,000 meters, as well as in the air.
What does "Trigger Depth" mean?
Within the trigger depth, it functions as a momentary switch—press to close the circuit, release to open. Once the water pressure reaches the trigger depth, the switch automatically activates to the ON state and remains ON if the depth is exceeded.
Is the trigger depth accurate?
There may be some variation in the trigger point. If precise depth activation is required, it is recommended to conduct multiple water pressure tests for calibration before use.
Will it be damaged by water pressure if the trigger depth is exceeded?
No, it won’t be damaged. The switch is designed to operate at depths up to 1,000 meters regardless of trigger threshold.
