Underwater GPS Operating Principle




1. Locator

The Locator is sending an acoustic signal which are picked up by the Receivers

2. Receivers

The four receivers are picking up the acoustic signal from the Locator

3. Topside

The topside positioning computer uses advanced algorithms to triangulate and calculate the position of the Locator based on the received signals from the Receivers

Topside Alternatives

Locator Alternatives


All Underwater GPS systems comes with a pre-loaded Graphical User Interface (GUI).

The GUI runs on the Master-D1 positioning computer and is accessed through a standard web browser.

  • Drag’n drop functionality
  • Map-view with absolute position
  • Grid-view with relative position
  • Live update
  • Points Of Interest
  • Diagnostic tools
  • OS independent (Windows/Mac/Linux)


Underwater GPS is extremely easy to deploy and start to use!

1. Mount Locator

2. Drop Baseline

3. Input Baseline in GUI

4. GO!


The four receivers can be delivered with cable lengths of 10, 50 or 100 meter. This opens up for very flexible deployment options, even on the largest boats.

Optimal Receiver Setup

When possible, try to spread the Receivers out so you have at least 2 meter between them. Different depths may increase performance.

Make sure the receivers are well submerged and prefferably below the splash zone where there might be air bubbles from waves etc.

Limiting Receiver Setup

If you are unable to deploy a square baseline, you might end up with some limitiations.

In the example below, all receivers are on one line. With such a setup it is not possible to decide which side (A or B) of the baseline your locator is. You have to limit the search area in the GUI to only one of the sides.


The range of an Underwater GPS system is limited by the power of the acoustic signal from the Locator and the software on the topside positioning computer.

All Locators support a range of 200 x 200 x 100 meters. The topside software will only search for the Locator inside this cube. If the Locator is moving outside this cube, the position will not show up in the GUI.


Underwater GPS uses a very robust operating principle with multiple receivers.

Combining the multiple receivers with extremely sophisticated software algorithms running on modern hardware, Underwater GPS excels where traditional positioning systems stop working.

The amazing performance comes to display especially when the environment is challenging:

  • Shallow water
  • Inside tanks or pools
  • Close to ship hulls
  • Inside fully populated fish farming cages
  • Inside subsea templates
New areas of application

This new level of robustness opens up for subsea acoustic positioning in areas and applications previously regarded impossible.

Read more about applications


In normal circumstances, you will typically experience an accuracy of ~99%. Translated into distance, this means the Locator will be positioned inside a ball of 1 meter diameter on 100 meter range.

Performance Testing

The video below shows how we performance test the system. By using RTK enabled GPS on a boat, we can generate a tracklog of the boat with ~1cm accuracy. Comparing that track log with the Underwater GPS tracklog we see an extremely high accuracy. The test below is done in shallow water (~6-8m depth) and large concrete walls surrounding the dock.

Available Underwater GPS Products

Underwater GPS Explorer Kit

Underwater GPS is the most robust acoustic positioning system on the market today!

Underwater GPS Modules

Build your own setup using separate modules

Spare parts