Disclaimer

AIS Data Accuracy Limitations

The vessel position data presented on HeyMariner is derived from Automatic Identification System (AIS) transmissions collected via terrestrial receiver networks and satellite AIS (S-AIS) platforms. While we endeavour to provide the most current and complete data available through our licensed data feed providers, users must be aware of the following inherent limitations of AIS data:

• Transponder dependency: AIS data is only generated by vessels with operational AIS transponders. Vessels that have switched off, malfunctioned, or are not required by law to carry AIS equipment will not appear in the platform, or will appear as a static last-known position that may be hours, days, or weeks out of date.
• Coverage gaps: terrestrial AIS reception is limited to approximately 40–74 nautical miles from shore receivers, depending on antenna height and atmospheric conditions. Vessels transiting the open ocean, polar regions, or remote waterways may only be visible via satellite AIS, which provides periodic snapshots rather than continuous tracking.
• Data latency: satellite AIS pass-over intervals mean positional data for vessels in mid-ocean may be delayed by minutes to several hours. Even terrestrial AIS feeds are subject to aggregation and processing delays. The timestamps associated with each position fix should always be checked.
• MMSI conflicts and data errors: some vessels transmit incorrect MMSI numbers, either through misconfiguration or deliberate manipulation. This can result in ghost tracks, misidentified vessels, or positions attributed to the wrong ship. HeyMariner cannot verify the authenticity of every AIS transmission received.
• AIS spoofing: malicious or fraudulent manipulation of AIS transponders — including GPS spoofing, replay attacks, and synthetic position injection — may result in false vessel positions being presented in our data feeds. We apply filtering algorithms to detect anomalies but cannot guarantee that all spoofed data is identified and excluded.
• Positional accuracy: AIS Class A transponders report position with a typical accuracy of 10 metres or better when a GPS-linked position source is available. However, older transponders, those using dead-reckoning fallback, or those with degraded GPS signal may report positions with substantially lower accuracy.

HeyMariner makes no warranty, express or implied, as to the accuracy, completeness, timeliness, or fitness for purpose of any AIS-derived positional data displayed on the platform. All positional data should be independently verified before being relied upon for any operational, commercial, or regulatory purpose.

Weather Data Advisory Notice

HeyMariner provides meteorological and oceanographic data overlays — including wind speed and direction, significant wave height, sea surface temperature, ocean currents, and tropical storm tracking — sourced from third-party numerical weather prediction (NWP) model providers and meteorological agencies.

This weather data is provided for situational awareness and general planning purposes only. It is subject to the following limitations:

• Forecast uncertainty: all meteorological forecast data carries inherent uncertainty that increases with forecast lead time. Conditions in remote ocean areas, particularly in the Southern Ocean, Bay of Bengal, and Arctic waters, may be modelled with lower accuracy due to sparse observational data.
• Model resolution: global NWP models used to generate ocean weather overlays typically operate at horizontal resolutions of 9–25 kilometres. Local sea-state conditions, coastal effects, and wind shadows caused by topographic features may not be accurately captured at this resolution.
• Update frequency: weather model outputs are updated on fixed cycles (typically every 6 to 12 hours). The displayed data may not reflect rapidly developing or rapidly deteriorating meteorological situations.
• Not an official forecast product: the weather data provided through HeyMariner is not an official meteorological service and does not replace professional voyage weather routing, meteorological officer advice, or warnings issued by national meteorological services such as the UK Met Office, NOAA, or WMO-affiliated agencies.

Users requiring weather information for voyage safety purposes should consult official marine weather forecasts, GMDSS weather broadcasts, Navtex messages, and qualified meteorological routing services. HeyMariner accepts no liability for any loss, damage, or injury arising from reliance on weather data presented through the platform.

Navigation Decisions

HeyMariner is expressly not a navigational aid and does not meet the technical or certification requirements for type-approved navigation equipment under SOLAS Chapter V or any flag state regulation. The platform must not be used as:

• A primary means of determining a vessel's own position at sea.
• A tool for collision avoidance, target acquisition, or closest point of approach (CPA) calculation in real-time navigational scenarios.
• A substitute for chart plotters, Electronic Chart Display and Information Systems (ECDIS), radar, AIS receivers fitted on board, or other type-approved navigation equipment.
• A system for planning passages in ice-covered waters, areas with restricted chart coverage, or any waters requiring specialist navigational expertise.

The Master and bridge watch officers of any vessel retain sole and absolute responsibility for all navigational decisions, for the safe conduct of the vessel, and for compliance with COLREGs, port authority requirements, traffic separation schemes, and all applicable maritime regulations. The availability, accuracy, or operation of HeyMariner in no way reduces, modifies, or transfers this responsibility.

HeyMariner shall not be liable for any grounding, collision, allision, loss of life, personal injury, cargo damage, environmental damage, or any other loss howsoever arising from any navigational decision made with reference to, or in reliance upon, data or information presented through the platform.

Maritime Regulatory Changes

The maritime industry operates within a complex and frequently evolving international regulatory framework administered by bodies including the International Maritime Organization (IMO), flag state administrations, port state control authorities, and regional organisations such as the Paris MOU and Tokyo MOU. HeyMariner may present regulatory information including:

• Port state control (PSC) inspection records, detention history, and deficiency data drawn from publicly available MOU databases.
• Emissions Control Area (ECA) boundaries and fuel sulphur limit information.
• Vessel certification status indicators based on data reported to international registries.
• Flag state blacklist and grey-list status derived from Paris MOU, Tokyo MOU, and similar memoranda.

This regulatory information is sourced from third-party databases and public records and may not reflect the most current status of a vessel, its certificates, or applicable regulations. IMO instruments are subject to amendment through the Marine Environment Protection Committee (MEPC) and Maritime Safety Committee (MSC), and their implementing legislation varies between flag states and port states. Regulatory requirements may change at short notice.

Nothing presented on HeyMariner constitutes legal or regulatory advice. Ship operators, shipowners, charterers, and maritime lawyers must consult the official IMO instruments, flag state circulars, port authority notices to mariners, and qualified maritime legal counsel to determine current regulatory obligations. HeyMariner accepts no responsibility for any regulatory non-compliance, fine, detention, or commercial loss arising from reliance on regulatory information displayed through the platform.

General Disclaimer

The information and data provided through the HeyMariner platform are supplied on an “as is” basis for general maritime intelligence and commercial situational awareness purposes. To the fullest extent permitted by applicable law:

• HeyMariner makes no representation or warranty of any kind, express or implied, as to the accuracy, completeness, reliability, or fitness for a particular purpose of any data, information, or content made available through the Service.
• HeyMariner shall not be liable for any direct, indirect, incidental, consequential, or punitive loss or damage arising from use of, or inability to use, the platform or any data obtained from it.
• HeyMariner does not warrant that the Service will be uninterrupted, error-free, or free from viruses, and accepts no liability for any loss arising from service interruptions, data feed outages, or technical failures.
• Links to third-party websites or data sources provided through the platform are for convenience only. HeyMariner has no control over and accepts no responsibility for the content, accuracy, or availability of those external resources.

Users of the HeyMariner platform are expected to exercise independent professional judgement when interpreting data and making decisions that affect vessel operations, commercial transactions, or regulatory compliance. The platform is a supplementary intelligence tool — not a decision-making system.

If you have questions about the scope of this Disclaimer or require clarification on the appropriate use of HeyMariner data for a specific operational context, please contact us at support@heymariner.com. For our full legal terms, see our Terms of Service and Privacy Policy.