The World’s first Iridium GMDSS terminal – distress, safety, and everyday connectivity in one Wheelmark approved system, with 100% global coverage.
In 2018, the IMO’s Maritime Safety Committee (MSC) recognized Iridium as Recognized Mobile Satellite Service (RMSS) for GMDSS as an alternative to Inmarsat C.
The LT-3100S GMDSS system is so far the only Iridium GMDSS terminal available. It meets all standards and certification requirements needed for GMDSS communications equipment (MED, Wheel mark).
LT-3100S GMDSS – developed and manufactured by Lars Thrane A/S – offers Distress Alert, Safety Voice, and Maritime Safety Information (MSI) as well as Ship Security Alert System (SSAS) and Long Range Identification & Tracking (LRIT).
PERFORMANCE
The LT-3100S GMDSS system has voice and data capabilities with 100% global coverage. The LT-3100S GMDSS system consists of a control unit, handset, and antenna unit. A single cable solution connects the control unit with the antenna unit. Using a standard coaxial cable, up to 500 meters of separation between the units can be obtained, giving freedom to mount the antenna in the best possible location, with free line of sight to the satellites.
The LT-3100S GMDSS system is designed for the Iridium GMDSS Safety Services and can be used as the primary satellite communication product on vessels, covering the basic communication needs in terms of connectivity between the ship and shore. The LT-3100S GMDSS system also provides voice, SMS, data, vessel tracking, and other Iridium services with competitive airtime rates, making it the perfect satellite communication product on board any vessel.
The LT-3100S GMDSS System is designed and built for the demanding and rough environment at sea and with an operational temperature range from -40⁰C to +55⁰C (-40⁰F to +131⁰F).
INSTALLATION
The LT-3100S GMDSS system is very easy to install. Everything is included in the box to get started with the installation and operating the LT-3100S GMDSS system. The control unit can be installed using either a bracket mount or flush mount. The antenna unit can be mounted using a pole mount for either 1.5″ or 2.0” pipes. The control unit has a large 4.3″ TFT display, from where the system can be operated with overview and ease. The built-in webserver can be used for service and maintenance.
More than 40 years of experience have been put into the design and construction of the LT-3100S GMDSS system, with an exceptional performance and specification level.
Distress and safety communication assured across Sea Areas A1, A2, and A3 — with genuine pole-to-pole reach over the Iridium® network, including the high latitudes and polar routes that other systems can't cover.
Type-approved for GMDSS service across Sea Areas A1, A2, and A3, with MED and Wheelmark certification — meeting the mandatory safety requirements for compliant maritime operation worldwide.
Powered by the Iridium® network, the LT-3100 delivers true pole-to-pole global coverage with competitive airtime rates — reliable connectivity on any ocean, in any conditions.
Distress Alert and Distress Call, Safety Calling and Safety Messaging, plus Maritime Safety Information (MSI) — the complete GMDSS safety toolkit, delivered over 100% global Iridium coverage.
Integrated Ship Security Alert System (SSAS) and Long Range Identification & Tracking (LRIT) bring security alerting and position reporting into the same certified system.
Support for remote Alarm Panels, a GMDSS Printer, and Bridge Alert Management (BAM) — so the LT-3100S fits cleanly into the vessel's wider bridge and safety architecture.
| Title | Version | Date added | Download |
|---|---|---|---|
| LT-3100S GMDSS User and Installation Manual Rev. 1.10 | 24-06-2026 | Download | |
| LT-3100S GMDSS Product Sheet Rev. 1.02 | 24-06-2026 | Download | |
| LT-3100S GMDSS SOLAS Fact Sheet Rev. 1.00 | 1.00 | 23-08-2023 | Download |
| Iridium GMDSS Design and Installation Guidelines | 23-08-2023 | Download | |
| ISO 9001:2015 DNV Certificate | 02-06-2026 | Download |
| Title | Version | Date added | Download |
|---|---|---|---|
| LT-3100S Application SW v1.08 | 1.08 | 02-06-2026 | Download |
| LT-3100S SW v1.08 Release Notes | 1.08 | 02-06-2026 | Download |
| LT-3100S SW v1.07 Release Notes | 25-06-2026 | Download | |
| LT-3100S SW v1.06 Release Notes | 25-06-2026 | Download | |
| LT-3100S SW v1.05 Release Notes | 25-06-2026 | Download | |
| LT-3100S SW v1.04 Release Notes | 25-06-2026 | Download | |
| LT-3100S SW v1.03 Release Notes | 25-06-2026 | Download | |
| LT-3100S SW v1.02 Release Notes | 25-06-2026 | Download |
| Title | Version | Date added | Download |
|---|---|---|---|
| IMO LRIT ASP Testing List (29-09-2023) | 29-09-2023 | 02-06-2026 | Download |
| LRIT ASP CLS Fulcrum Contact Details | 1.02 | 02-06-2026 | Download |
| LRIT ASP Pole Star Contact Details | 1.00 | 02-06-2026 | Download |
| LRIT ASP Kemilinks Contact Details | 02-06-2026 | Download | |
| LLT-3100S GMDSS System LRIT Troubleshooting | 02-06-2026 | Download |
Please contact our GMDSS Certified Partners to obtain information about our online GMDSS training platform.
| Control Unit | Weight: 658 g (1.45 lbs) |
|---|---|
| Handset Unit | Weight: 290 g (0.64 lbs) |
| Antenna Unit | Weight: 687 g (1.51 lbs) |