A new data exchange system for ships and other marine craft including yachts is coming
VDES or the VHF Data Exchange System will come into use, with mandatory compliance for SOLAS-regulated vessels in January 2028. VDES uses the Marine VHF radio band as a send and receive radio communication system to operate between ships, shore stations and satellites. It enhances AIS – the Automatic Identification System, adding ASM – Application Specific Messages and VHF Data Exchange (VDE), both from satellites and shore stations operating across multiple frequencies to give an expected 12 channels covering ship information, weather, navigation data and operational data.
The system will use your existing antenna to provide 32 times higher data rates than traditional AIS, with the 12 channels in one box including two frequencies for satellite-based long-range AIS, two frequencies for sending and receiving AIS-based messages, four channels for up-and-downlink terrestrial-based data, and four channels for up-and-downlink satellite data.
The change has meant that marine VHF channels have been axed (from January 2024) to release their bandwidth for VDES. The Channels which no longer operate on VHF radio sets are 24 to 28, and 84 to 86 with 96 going in Belgian waters.
The development is to migrate non-ship-to-ship traffic off AIS so that AIS remains primarily for collision avoidance, while other marine-safety updates migrate to the other VDES channels. Current AIS devices will continue to work, unaffected, but the new system promises more efficiency, with better and broader information. While real time chart corrections and nav warnings will be a huge bonus the offshore real-time weather data could be a game changer, especially with recent cuts to the Long Wave BBC Shipping forecasts.
However VDES is not envisaged as being a free service and while it is often cited as affordable – with some estimates saying it will halve the cost of a comparable satellite services that could mean a £25 to £30 per month minimum sub.
How soon yachtsmen will take it up will depend on how much safer the system will make us feel. For instance earlier this year, in January 2026 Starlink, the current darlink for cruisers wanting high speed internet at sea, doubled the data consumption for its Roam Unlimited users from 50Gb to 100Gb per month on the £50/$50USD plan – with its Mini dish (consuming 20–40 watts (1.5–3.5amps/hr at 12V) during normal operation, typically retailing for under £250. Dan Houston
Updated from a 2018 post – see below.
IALA Seminar on VHF Data Exchange System (VDES) & ENAV Intersessional meeting
News from IALA (International Organization for Marine Aids to Navigation, previously known as International Association of Lighthouse Authorities)
A one-day IALA Seminar on VHF Data Exchange System (VDES) was held at the YourWorld Conference Centre in Yiwu city on Monday 16 July 2018. The Seminar was attended by over 100 delegates and followed by a four-day meeting of the IALA Working Group on Communications, part of the ENAV Committee. The two events were hosted by China MSA and IALA, and sponsored by Zhe Jiang SIST Co., Ltd.
The Seminar highlighted developments in VDES, including the possible use of VDES to support position, navigation and timing (PNT) through VDES R-Mode.
Following the Seminar, the Working Group on Communications met from the 17th to the 20th. An objective of the working group meeting included reviewing and improving the IALA Guideline 1139 to capture the technical description of VDES, with the expectation of updating a new draft version of this Guideline at the ENAV 22 Committee meeting in October.
VDES is a VHF digital communications system specifically designed for the Imaritime environment. VDES is expected to carry maritime safety information and other ship data information, with both terrestrial and space components. As a system, VDES includes and protects the existing AIS channels, which will remain unchanged, while adding extra channels for Application Specific Messages and for digital data transmission. A major driver for VDES is to reserve the AIS channels for safety of navigation, moving to other channels the increasing numbers of non-safety related messages now being imposed on the AIS frequencies.
VHF Data Exchange System (VDES) – What is VDES? VHF Data Exchange System (VDES) is a radio communication system that operates between ships, shore stations and satellites on Automatic Identification System (AIS), Application Specific Messages (ASM) and VHF Data Exchange (VDE) frequencies in the Marine Mobile VHF band.
- What is the difference between VDES and AIS? AIS is a component of VHF Data Exchange System (VDES) which operates using the Gaussian Minimum Shift Keying (GMSK) modulation scheme, other components of VDES will use higher capacity modulation schemes.
- Why VDES? The VHF Data Exchange System (VDES) is seen as an effective and efficient use of radio spectrum, building on the capabilities of AIS and addressing the increasing requirements for data through the system. New techniques providing higher data rates than those used for AIS is a core element of VDES. Furthermore, VDES network protocol is optimized for data communication so that each VDES message is transmitted with a high confidence of reception. VDES supports e-Navigation and provides access to the Maritime Cloud.
- What frequencies does VDES use? VHF Data Exchange System (VDES) comprises a suite of channels in the Maritime mobile VHF band, which are detailed in the IALA VDES Guideline on the IALA website.
- What is the roadmap for VDES? VHF Data Exchange System (VDES) will continue to be developed over the next few years in accordance with the roadmap published in the VDES Guideline.
- Further information on VHF Data Exchange System (VDES) can be found in the IALA Guideline on VDES which is located on the IALA website
here: https://www.iala.int/product-category/publications/guidelines/
