Legal

Terms of Service & End User License Agreement

Last updated: August 2026

Please read these Terms of Service ("Terms") carefully before downloading, installing, or using the VHF Radio Assistant mobile application ("the App") or navigating the website vhfradioassistant.com ("the Site"). By accessing or using the App and Site, you agree to be bound by these Terms.

These Terms constitute a legally binding agreement between you ("User" or "Master") and VHF Radio Assistant Ltd ("the Company", "we", "us", or "our"), a company registered under the laws of the United Kingdom.

1. Scope of Service & No Maritime Advice

VHF Radio Assistant is a navigational and communication helper tool designed to assist mariners in formatting radio scripts, monitoring situational awareness, and calculating potential intercept pathways.

Not an emergency system: the App is not a replacement for Global Maritime Distress and Safety System (GMDSS) equipment, an Emergency Position Indicating Radio Beacon (EPIRB), a fixed or handheld marine VHF radio, or any mandatory vessel safety gear.
Secondary aid only: all information, automated or manual script generations, proximity alerts, and vessel interception calculations provided by the App are for situational awareness and reference only. The Master of the vessel retains ultimate, overriding responsibility for safe navigation, maintaining a proper lookout, and legal radio operations under international maritime laws (COLREGs).

2. Custom Scripting, Voice Warmup & Layout Disclaimer

The App allows users to customise operator command suites, write or edit transmission text, configure Voice Warmup modules, and choose preferred text display formats.

User-generated content: the Company does not review, approve, or vet user-edited or custom-created scripts, presets, or replies. You assume total responsibility for ensuring that any text or audio broadcast generated by your custom modifications complies with local maritime laws, licensing restrictions, and standard international radio protocols.
Voice Warmup & pacing modalities: the App provides a "Voice Warmup" utility incorporating "Pre-Trip Vocal Pacing" (a rhythmic visual breathing guide to help practice relaxed breathing, gentle vocal onset, and smooth word blending) and a "Paced Script Display" (which adds wider word spacing, breathing markers, and highlighted phonetics to the screen). Toggling between the Standard Layout and the Paced Layout, or switching between phonetic and normal text, changes the visual presentation layout only — it never alters the actual legal maritime words spoken or generated.
Text-to-speech output: the text-to-speech engine broadcasts text exactly as it appears or as configured by the user. The operator can manually halt or cancel the text-to-speech audio broadcast at any second via the touchscreen interface. The Company assumes zero liability for garbled transmissions, audio distortions, or illegal over-the-air broadcasts resulting from user-modified script text or pacing selections.
Channel numbers are for reference only: any VHF channel number recorded against a Marina, VTS/Harbour Master, Coastguard, lock, or other local directory entry is provided for convenience, based on publicly available information at the time of development. Working channel assignments for ports, marinas, VTS stations, and other authorities can and do change over time. The user is solely responsible for independently verifying the correct, current working channel for any station before transmitting — via the relevant harbour authority, an official nautical almanac, or a current Notice to Mariners — and for updating that entry in the App's local directory for the area if it no longer matches. The Company accepts no liability for a call made on an incorrect or outdated channel.

3. Vessel Interception & Target Tracking Disclaimer

The App includes a vessel intercept calculation feature utilising live or historical Automatic Identification System (AIS) and Global Positioning System (GPS) data to calculate interception courses toward target vessels (including stopped, disabled, or drifting vessels).

Mathematical estimates only: intercept paths, headings, required speeds, and time-to-intercept metrics are purely mathematical estimates based on data inputs that may be delayed, incomplete, or corrupted.
Drifting and unpredictable targets: the user explicitly acknowledges that a target vessel's speed, heading, and operational state can change instantly. For drifting or unpowered vessels, environmental factors (currents, tides, wind leeway) are unpredictable, and the Company does not guarantee the accuracy of interception tracking for dynamic, unpowered, or erratic targets.
Master's overriding authority: the execution of any intercept manoeuvre is done entirely at the user's risk. The user must maintain a proper visual and radar lookout at all times. You must never prioritize an App-calculated intercept course over safe piloting, safe speed, or the immediate duty to avoid a collision.
COLREGs compliance: users must comply strictly with the International Regulations for Preventing Collisions at Sea (COLREGs). The App's intercept feature must never be used in a manner that creates a risk of collision, violates right-of-way rules, or endangers either vessel.
Collision Risk View — decision support, not a certified collision-avoidance system: when a CPA alert is active, the App can project a trial course change at the vessel's current speed and indicate the resulting distance to the tracked vessel, and will attempt to flag if that trial course creates a new collision risk with another vessel the App is currently tracking. This evaluation is limited strictly to vessels visible to the App via AIS at that moment, and assumes the vessel's speed remains unchanged from the trial — it cannot account for vessels not broadcasting AIS, other water users, navigational hazards, a simultaneous change of speed, or any risk outside its tracked data. It is a decision-support aid only, not a certified collision-avoidance system, and does not relieve the user of the primary duty to maintain a proper visual and radar lookout at all times under COLREGs. The Company accepts no liability for a collision, near-miss, or unsafe manoeuvre arising from a course evaluated, suggested, or not flagged by this feature.
MOB Telemetry Cushioning data limits: the App utilises a per-MMSI rolling 3-minute window applying a 20% proportional trimmed-mean speed filter and vector-component heading averaging to smooth wave-induced target jitter. The user explicitly acknowledges that severe sea states, antenna drowning, or packet loss can drop the message count inside a burst below the minimum statistical sample threshold. The Company assumes zero liability if calculation delays, un-smoothed erratic vectors, or vector-parsing limits result in tracking latency or a failed interception manoeuvre during an active rescue attempt.

4. Hardware, Connectivity & Bluetooth Sync Disclaimer

The App features integration that interfaces with third-party hardware, including but not limited to USB audio interfaces (e.g. Digirig Mobile), cabling, and marine VHF transceivers. It also features a custom Bluetooth Low Energy (BLE) pipeline for cross-platform data sharing.

No transmission guarantee: we do not guarantee that the App will successfully key your radio transmitter, modulate audio perfectly, or successfully complete a broadcast over the airwaves. It is your sole responsibility to ensure all physical connections are secure and radio channels are manually verified prior to transmitting.
Cross-platform BLE pipeline dropouts: device-to-device Bluetooth syncing of custom buttons, directories, or saved marinas relies on short-range wireless protocols. The App supports peer-to-peer data sharing across mixed operating systems (including Android-to-Android, Android-to-iOS, iOS-to-iOS, and iOS-to-Android). The Company is not responsible for data loss, corrupted profiles, or failed target transfers resulting from local signal interference, operating system background process restrictions, hardware disconnects, or distance dropouts between master and crew devices.
NMEA and wireless streams: the App allows direct connection to onboard shipborne hardware (including but not limited to Vesper Marine, NMEA multiplexers, and local TCP/UDP routers). Wireless networks on maritime vessels are subject to heavy interference and power interruptions. The Company assumes zero responsibility for delayed tracking telemetry, stale vessel vectors, or calculation failures resulting from network hardware configuration errors on the host vessel.

5. AIS Data and Map Accuracy

Live tracking, Closest Point of Approach (CPA) calculations, vessel intercept courses, and navigation charts depend entirely on external GPS feeds and local/networked Automatic Identification System (AIS) broadcast availability.

No reliance for collision avoidance: ground truth target tracking and target positioning must always be verified visually and via type-approved shipborne radar. We assume no liability for AIS data lag, dropped signals, missing targets, or incorrect intercept/CPA/TCPA calculations caused by third-party data streams.
Offline charts: offline marine charts and proximity indexes (such as the "Rule of Three" directory) are provided for convenience and must not be used as the primary tool for navigation. Official hydrographic paper or electronic charts must be used.

6. AIS Safety Related Messages (SRM) Reception

The App features the capability to receive, decode, and display digital data transmissions broadcast by third-party vessels or shore stations, including but not limited to AIS Addressed Safety Related Messages (Message 12) and AIS Safety Related Broadcast Messages (Message 14), on your device's screen. The App does not transmit, forward, or relay Message 12 or Message 14 data to any other vessel; it is a passive receiver of such messages only.

No reception or decoding guarantee: the Company provides no guarantee that any Message 12 or Message 14 transmission broadcast by a third-party vessel or station will be successfully received, decoded, or displayed by the App, whether due to range, signal interference, transponder configuration on the sending vessel, or any other cause outside the Company's control.
Distraction and interpretation risks: the user acknowledges that reviewing incoming digital text alerts may act as a navigation distraction or be misinterpreted. The user is entirely responsible for how they act upon the content of any message received, including any voice response generated with the assistance of the App's Operator Command Suites.
Voice channel primacy: digital SRM text alerts must never be relied upon as the sole basis for collision avoidance, right-of-way negotiations, or safety-of-life manoeuvres. Traditional maritime voice communications (VHF Channel 16 / local port channels) and strict adherence to COLREGs must always take precedence over text-based information.
No independent verification: the Company does not verify the accuracy, authenticity, or intent of any Message 12 or Message 14 content received from a third-party vessel or station. The user assumes all responsibility for exercising independent judgement before acting on received message content.

7. Single-Handed MOB Automated Distress Relay & Over-The-Air Commands

The App contains an advanced, optional integration designed to trigger an automated VHF voice Mayday broadcast through a connected fixed transceiver when a registered personal safety beacon activation is verified.

Dual-device dependency & verification: this feature requires the user to manually link and register an independent, type-approved personal safety beacon inside the App. The App acts solely as a secondary relay engine; it will not initiate an automated broadcast unless the physical personal beacon is successfully activated first.
Mandatory mechanical isolation switch: to mitigate the severe risk of accidental transmissions, software loops, or hardware short-circuits jamming Marine Channel 16, the user is strictly required to install a physical, mechanical A/B isolation switch between the radio's hand microphone and the Digirig interface. The user agrees to keep this switch set to the hand microphone position (Position A) during standard operation, and only toggle to the automated circuit (Position B) when entering active, solo deck operations.
Broadcast repeat schedule & fixed cap: once triggered, the automated broadcast repeats at approximately 4-minute intervals, aligned with GMDSS guidance for repeating an unacknowledged distress alert. The broadcast repeats a maximum of 4 times, after which it stops automatically and permanently for that situation — this fixed limit is independent of the STOP command, SAR proximity detection, or any other condition, and applies regardless of whether any acknowledgement has been received. The App continues to accept and respond to VL, VD, and ML queries after the broadcast cap is reached. The user acknowledges that after the 4th broadcast, no further automated distress transmissions will be made regardless of whether the situation remains unresolved, and that reliance on this feature beyond that point is entirely at the user's own risk.
Remote override architecture & custom NMEA parsing: the system incorporates a network decoding engine that reads targeted data packets over the shipborne NMEA configuration. The operator acknowledges that the App will actively intercept and process addressed remote data commands from units identified by MMSI prefix (e.g. 00 for coastguard, 111 for SAR aircraft). This identification is based on the sender's self-declared MMSI number and is not a cryptographic or otherwise verified authentication of the sending unit's identity. Receipt of the text string "STOP" immediately halts any transmission currently in progress and silences the automated broadcast loop, and the App transmits a sender-aware spoken acknowledgment over the radio confirming receipt. A repeated or duplicate "STOP" for the same situation is disregarded once the first has been processed. Sentences routing "ML" (MOB Location), "VL" (Vessel Location), and "VD" (Vessel Description) will instantly update active script generation targets on screen and dynamically refresh the spoken text-to-speech audio outputs.
SAR proximity auto-stop: independently of the STOP command, the App monitors ordinary AIS broadcasts for any vessel self-identifying as AIS ship type 51 ("Search and Rescue vessel"). If such a vessel's reported position comes within approximately 2 nautical miles of the beacon's last known position, the App automatically halts the repeating broadcast without requiring any command from the SAR unit. This distance threshold is based on the personal safety beacon's own approximate standalone range and assumes the SAR unit will be able to receive the beacon directly at that range. The Company does not verify or guarantee the accuracy of any vessel's self-broadcast AIS ship type, and accepts no liability if a vessel incorrectly identifying as, or failing to identify as, ship type 51 causes the broadcast to stop prematurely or to continue longer than necessary.
Strict indemnity for network failures: the Company guarantees no operational uptime or parsing continuity for custom NMEA data strings. If a local wireless multiplexer drops, cabling faults, or message packet corruption prevents the software from executing an over-the-air "STOP" instruction, the user retains exclusive liability for any continued channel jamming or associated regulatory enforcement fines.

8. Subscriptions, Payments & Billing Policies

All purchases, monthly/annual recurring subscriptions, and lifetime access options are processed via third-party mobile application storefronts (e.g. the Apple App Store or Google Play Store).

Storefront authority: billing, renewals, payment processing, and cancellations are governed entirely by the terms and platform policies of the respective app store provider.
Refunds: all refund requests must be directed to and handled by the mobile storefront through which the purchase was made. The Company cannot directly process, modify, or guarantee refunds for storefront transactions.

9. Limitation of Liability

To the maximum extent permitted by applicable law, in no event shall VHF Radio Assistant Ltd, its directors, developers, employees, owners, or affiliates be liable for any direct, indirect, incidental, special, or consequential damages whatsoever (including, without limitation, damages for loss of vessel, property damage, maritime salvage costs, personal injury, loss of life, or data loss) arising out of the use of or inability to use the App — including any manoeuvres executed via the vessel intercept feature, custom-edited communication scripts, cross-platform Bluetooth syncing issues, automated MOB trigger loops, layout adjustments, or remote over-the-air deactivation or position payload string parsing and vocal speech engine rendering failures — even if advised of the possibility of such damages.

In no event shall the Company's total cumulative liability to you for all claims, losses, or causes of action arising out of or relating to these Terms or the App exceed the total amount actually paid by you to the Company for the App or any subscription during the twelve (12) months immediately preceding the event giving rise to the liability. Nothing in these Terms excludes or limits the Company's liability for death or personal injury caused by negligence, for fraud or fraudulent misrepresentation, or for any other liability which cannot lawfully be excluded or limited under the laws of England and Wales.

10. Governing Law & Jurisdiction

These Terms, and any dispute, controversy, or claim arising out of or in connection with them, their subject matter, breach, termination, or validity, shall be governed by and construed in accordance with the laws of England and Wales. The courts of England and Wales shall have exclusive jurisdiction to settle any such dispute or claim, without prejudice to any mandatory consumer protection rights you may have under the law of the country in which you are resident.

11. Severability

If any provision of these Terms is found by a court of competent jurisdiction to be invalid, illegal, or unenforceable, that provision shall be modified to the minimum extent necessary to make it valid and enforceable, or if it cannot be so modified, shall be severed, and the remaining provisions of these Terms shall remain in full force and effect.

12. Changes to These Terms

We may update these Terms from time to time, including to reflect new features, changed functionality, or legal and regulatory requirements. We will notify you of any material changes by posting the revised Terms on this page and updating the "Last updated" date at the top. Your continued use of the App after any such changes take effect constitutes your acceptance of the revised Terms.

13. Contact Information

For any legal enquiries, data protection requests, or questions regarding these Terms, please contact the Company at Get in touch.