Water Linked Locator-S1


The Locator-S1 is a beacon for the Water Linked positioning system. This locator is synchronized via GPS time at the surface and does not require any wires in the tether for operation so it can be used with the Fathom Slim Tether.

In stock

HS Code: 8512.30.30

Product Description

The Locator-S1 is a digital hydro acoustic locator device with an internal GPS based time sync module.

The Locator-S1 does not require tether integration for top-side communication. It only requires external power 10-18V to be provided from the underwater vehicle. Time-sync with the top-side is achieved using its internal GPS. That makes it perfect for integration with ROVs that don’t have an extra twisted pair in their tethers, such as a BlueROV2 with the Fathom Slim tether, or for fiber optic tethers.

As the Locator-S1 does not carry its own depth sensor, the depth needs to be provided from the underwater vehicle (ROV etc.) to the topside Master-D1 using the software API. Example of how to perform this can be found here.

This integration is already done if using an ArduSub vehicle (like the BlueROV2).

Some Locator-S1 attributes can be configured using an integrated I2C interface. This configuration is optional and not required for normal operation.

Before deployment in water, the Locator-S1 needs to achieve a GPS lock. The integrated status-LED shows the condition of the GPS lock.

It comes standard with a 1 meter cable (with preinstalled cable penetrator) for easy integration with ROVs like the BlueROV2.


  • GPS based sync removes all tether requirements enabling very easy integration with any ROV.
  • Extremely small size making it perfect for even the smallest underwater vehicles.
  • Highly robust operation in areas with reflections (shallow water, around installations etc.)



Tether IntegrationNone
Topside API IntegrationDepth
Sync methodGPS Lock
Time before re-sync6 hours
Position updates4 times per second
Range100 m330 ft
Accuracy<1% of range
Supply Voltage10-18 V
Peak Current60 mA at 12V
Power ConnectorNon-Insulated Spades
Data Connector3 position 0.1” (2.54mm) Crimp Connector Housing
Length77 mm3.03 in
Diameter30 mm1.18 in
Weight (in air)52 g1.83 oz
Depth Rating300 m984 ft
Body MaterialPEEK
Operating Temperature-10 to 60 °C14 to 140 °F

Wiring Interface

Positive (10-18V)Orange
UART TXBrown/White

Terminal Interface

The Locator-S1 has a simple UART interface which is used to change the channel of the locator.

Baud rate9600
Data parity stop8N1
Flow controlNone


Locator-S1 Datasheet

Water Linked Locator Comparison

3D Models

3D STP and STL files of mounting bracket

Revision History

28 March 2019

  • Added pre-installed penetrator and power spades.

01 March 2018

  • Initial Release


Note: Specific instructions for the Locator-S1 are not yet complete, but the below guides can be used as a reference.

Water Linked BlueROV2 Integration

Integrate the Water Linked Underwater GPS Developer Kit into your BlueROV2 to see where the ROV is on a map!

LED Indicator

  • No green light: Power is off and the unit is not ready for diving.
  • Flashing green light (fast): Searching for GPS lock. The unit is not ready to dive.
  • Fixed green light: GPS lock is achieved. The unit is ready to dive.
  • Flashing green light (slow): GPS lock has been achieved but lost. The unit is ready to dive.


Blue Robotics Forum – Water Linked Acoustic Products

Water Linked Forum – Underwater GPS