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Choose range spec

100 or 300 meter range. Select the version that suits your needs.


Quick deploy antenna

No need for separate receivers makes for a less resource demanding operation.


Full featured GUI

Access the Graphical User Interface through any standard web browser.

How it works:

Operating principle

You can choose between using a compact antenna or separate cabled receivers as your receiving baseline.

The antenna is quick and easy to set up while the separate receivers will enable very flexibly designed baselines. Both supports the full 300 meter range.


1. Locator

The Locator transmits an acoustic signal which are picked up by the Receivers.

2. Baseline

The antenna or separate Receivers picks 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 antenna/receivers.


See the range difference between the R100 and R300.


R100 or R300

Underwater GPS G2 comes in two different range versions; R100 and R300 where the number indicates the maximum range in meters between the Locator and Antenna/Receivers.

Cylindric Area

The operational area is designed as a cylinder with a radius of 100/300 meters and a depth of 100/300 meters.

Hard Limit

The 100/300 meter range is a “hard limit”, meaning that once the Locator moves outside that range, the position will not be calculated.

Acoustic + Software

The range is limited by the acoustic signal from the Locator and the software running on the Master-D1 positioning computer.

Limiting the search area

If you know you won’t need the full cylindric search area, it is beneficial to the performance of the system to apply some limits.


Limiting Range

You can reduce the radius of where the system will search for the locator. This is a great idea if you are operating in a confined space like water tanks, pools, fish cages or similar.

Reducing the range even in the open ocean may give you a better performance on short distances.

Limiting Area

You can limit which part of the cylinder you want to operate within. This should be done if there are obstacles like land or other no-go places for your ROV.

Reducing the area even in the open ocean may give you a better performance.

Limiting Depth?

It is not possible or needed to limit the depth. All Underwater GPS systems relies on a separate pressure sensor to provide the depth of the locator.

Underwater GPS G2 vs Explorer Kit


With the new G2 you can now operate out to a range of 300 meters. This makes the G2 the perfect underwater positioning system for operating in most situations you are ever likely to encounter.


The new G2 system has a completely rewritten positioning algorithm. Several years have gone by since we launched the Explorer Kit and thousands of hours of new research has gone into the new positioning algorithm making it better than ever!

Lots of upgrades

Based on customer feedback on the old Explorer Kit, we have added lots of new features to the G2 system. Built-in WiFi, Quick deploy antenna and an upgraded GPS are just some examples.

  G2 R100 G2 R300 Explorer kit (obsolete)
Max range (meter) 100 300 100
Performance in open water Excellent Excellent Good
Performance in reflective areas Excellent Excellent Good
Upgradable to 300 meter range Yes N/A No
WiFi Yes Yes No
Quick deploy antenna Yes Yes No
NMEA 0183 ports 3 3 0
On board IMUs 2 2 1
On board satellite GPS 10 hz, 72 ch 10 hz, 72 ch 1 hz, 66 ch
Satellite GPS battery backup Yes Yes No
Integrated battery tray Yes Yes No
Future SW upgrades Yes Yes No
Dedicated power switch with LED Yes Yes No


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Configure and buy

Full featured GUI

All underwater GPS system is supplied with a pre-loaded Graphical User Interface (GUI). The GUI runs on the G2 Topside and is accessed through a standard web browser.


  • Drag and drop functionality
  • Map-view with absolute positioning
  • Grid-view with relative positioning
  • Live update
  • Points of Interest
  • Diagnostic tools
  • OS independent (Windows/Mac/Linux)

Video: Shows the previous generation GUI.

Getting started

Underwater GPS G2 is extremely easy to deploy and start to use!

G2 Antenna Baseline solution

Mount-Locator1. Mount Locator

Drop-Baseline2. Deploy antenna

gps_43. GO!

G2 Custom Baseline solution

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.

Mount-Locator1. Mount Locator

Drop-Baseline2. Drop Baseline

gps_33. Input Baseline in GUI

gps_44. GO!


Optimal Receiver Setup

When possible, try to spread the Receivers out so you have at least 2 meters between them. Placing the receivers at different depths may increase performance.

Make sure the receivers are well submerged and preferably 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 to the left, 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 benefits of the G2 are truly appreciated when working in the most challenging environments.

Combining the multiple receivers with extremely sophisticated software algorithms running on modern hardware, Underwater GPS G2 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


By utilising a Short BaseLine (SBL) principle the G2 is both stable and accurate, positioning the Locator to within 1 meter at 100 meter range

Performance Testing

The video below shows a performance test of the G2 which is mounted to a boat that is fitted with an RTK enabled GPS.

The RTK GPS provides ~1cm accuracy positioning of the boat and allows us to generate a tracklog for the boat as it navigates around the marina. We then have a tracklog for the GPS and for the G2.

By overlaying the GPS tracklog with the G2 tracklog we demonstrate how reliable and accurate the G2 is, despite the difficulties associated with acoustic positioning in shallow water (~6-8m depth).

Would you like to discuss your underwater navigation needs with us?

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