
UGPS Accessories and upgrades
Specialized projects call for specialized equipment. Below you will find details on the range of accessories that can be supplied to support the installation of the G2 system. These accessories have been chosen to enhance the user experience and offers the ability to configure you G2 system differently to meet new requirements.
Locators
In a USBL (Ultra-Short Baseline) or SBL (Short Baseline) system, a locator is a transponder or acoustic beacon attached to the underwater target (such as an ROV, diver, or other equipment). It emits an acoustic signal that is picked up by the system's transceivers or hydrophones.
The system uses these signals to calculate the target's position based on the time of flight, signal strength, and angle of arrival. This enables real-time tracking of the underwater target's location relative to the surface or another reference point.
Which locator should I choose?
The Water Linked Underwater GPS G2 system is an exceptionally reliable positioning system that can be operated with 3 different locators. When you purchase a
U1 locator
The U1 Locator is a battery-powered locator with an integral depth sensor. This allows it to be used without the need for a direct connection to the G2 Topside. Customers often choose the U1 Locator if they want a wireless system (perfect for AUVs and divers).
D1 locator
The D1 Locator has an integrated depth sensor and therefore can be used with the G2 system without the need for additional sensors. Simply connect the D1 Locator directly to the G2 Topside and you will be able to accurately track the position of any platform the D1 Locator is fitted onto.
A1 locator
The A1 Locator is the smallest of all the locators. It must be physically connected to the G2 Topside, either directly or through a full system integration. As depth is not measured by the A1 Locator, this information must be provided by the user and delivered to the G2 Topside using the Water Linked API.


D1 Locator
- Fixed, integrated solution
- Must be connected to G2 Topside with our cable
- Integrated depth sensor

A1 Locator
- Fixed, integrated solution
- Must be connected to G2 Topside with own cable
- Smallest of all the locators
- No integrated depth sensor
UGPS Topside
The topside of a Short Baseline (SBL) system is the brain of the operation—it receives underwater signals, processes them, and calculates the exact position of the tracked object (like an ROV, AUV, or diver).
How Does It Work?
1: Listens for Underwater Signals
- The topside is connected to several receivers placed in the water.
- These receivers detect acoustic signals sent from the underwater locator (transponder).
2: Measures Signal Timing
- The topside calculates how long it takes for the locator’s signal to reach each receiver.
- Because sound moves at a known speed underwater, this helps determine the locator’s distance from each receiver.
3: Calculates the Exact Position
- Using triangulation, the topside combines distance data from multiple hydrophones to pinpoint the locator’s exact location in the water.
- The topside has an integrated GPS receiver, allowing the absolute position of the locator to be displayed in real-time.
G2 Topside - Pelican Case
This topside case is normally delivered as part of a complete Underwater GPS G2 system. But if you already own a Water Linked locator and baseline, you can purchase this product to get a complete system.

UGPS baseline
The UGPS can be set-up in two different ways. The original UGPS Explorer (G1) series was only available with 4 separate hydro acoustic receivers, while the UGPS G2 series is mostly supplied with a UGPS Antenna. The GPS Antenna comprising 4 receivers mounted to a collapsable aluminium frame for quick and easy system set-up. You can order the antenna and the separate receivers individually here if you want to upgrade your older system or if you want a custom set-up.

UGPS Antenna
The Antenna makes deployment of the Underwater GPS baseline fast and easy. It comes included with the UGPS G2 system. This antenna has 4 x Receiver A1 integrated and can be ordered to upgrade a system that was originally purchased to use the 4 x Receiver D1 separately.
D1 Receiver
If you want to set up a baseline with separate receivers, you could order them individually. A UGPS system requires 4 x Receiver D1 to work properly.

Integration kits

BlueROV2 Integration Kit
This kit provides the Homeplug card and a few additional cables to allow the Underwater GPS G2 system to seamlessly integrate with the BlueROV2.
Brackets

GoPro bracket for U1 Locator
This bracket will fit perfectly between your U1 Locator and your existing GoPro mount.

Blueye bracket for U1 Locator
This bracket will fit perfectly between your Locator-U1 and your Blueye Pioneer.
Upgrades
UGPS G300 upgrade
Upgrade your UGPS G2 system from 100 meters (R100) to 300 meters (R300) and unlock a significantly larger operational area for underwater positioning.
Expert Support

Expert Support Pack (4 Hours)
Do you need some special adaptation or integration of your Water Linked product? Get the help you need by utilizing our expert developers in your project. This support pack includes 4 hours of expert assistance.