Safety, Navigation, Weather and Anchor Watch Notice

Mermaid assists; the skipper decides. Never use Mermaid as the sole or primary source for navigation, weather, depth, anchoring, collision avoidance, lookout, emergency response, vessel condition or crew safety.

1. Nature of the Service

Mermaid is planning, coordination, evidence and assistance software. It helps organise boat and charter context; route options and lookahead warnings; weather presentations with source-age information; anchorages, marinas and community observations; the anchor watch and selected crew notifications; safety briefings and crew acknowledgements; inspection and photographic evidence; the logbook and trip replay; and optional instrument (NMEA) enrichment.

Mermaid is not a certified electronic chart display and information system or electronic chart system; an official hydrographic chart, notice to mariners, sailing direction or pilot book; an autopilot, radar, AIS, collision-avoidance or vessel-control system; an official meteorological or marine-warning service; a Global Maritime Distress and Safety System, emergency beacon or emergency service; a marine survey, damage appraisal, safety certification or charter-company acceptance; a mandatory official ship's log; or a substitute for a properly qualified, rested and attentive skipper and crew.

2. Non-delegable skipper responsibility

The skipper remains responsible for the vessel, the voyage and the people on board. Using a Mermaid feature, receiving a warning, obtaining a crew signature or sharing an alarm does not transfer or reduce that responsibility. Before and during a voyage the skipper must comply with flag-state, coastal-state, port, charter and local rules; use current official charts and publications with their corrections and notices; keep a continuous visual and auditory lookout; use and cross-check onboard instruments and independent sources; prepare and keep updating a passage plan; account for actual draft, air draft, tide, current, sea state, visibility, traffic, weather and crew capability; follow harbourmaster, marina, coast guard and owner instructions; ensure safety equipment is present, accessible, maintained and understood; and stop, alter or abandon a plan when conditions, data or competence require it. A route shown in Mermaid is not permission or proof of safe passage, and the absence of a warning does not mean that no hazard exists.

3. Route and chart limitations

Mermaid presents route options from route corridors and the geospatial layers it has. It may fail to include or correctly position shoals, rocks, wrecks, cables and underwater works; buoyage changes, temporary marks or uncharted hazards; traffic separation schemes, prohibited zones or military activity; bridge and overhead clearances; local speed, anchoring, environmental or seasonal restrictions; current, tide, chart datum and rapidly changing depth; construction, dredging, closures or port-control instructions; and traffic, floating objects or another vessel's movement. Map and bathymetry content is generalised, satellite-derived, community-derived, delayed or licensed for contextual display rather than primary navigation. Plot and verify the route on official material suitable for the vessel and area. Zoom level, colour, visual smoothness and route optimisation say nothing about survey quality or clearance.

4. Weather limitations

Weather models describe probabilities and expected conditions, not certainty. Mermaid displays fused and transformed information from several sources: baseline forecast, gust layers, field tiles, coverage and source age. Risks include model error and spatial averaging; delayed source updates or caching; missing coastal, local, convective or terrain effects; gusts, squalls, thunderstorms and waves exceeding the presentation; network or provider outages; a wrong location, time zone, unit or selected layer; and fallback to lower-resolution or older data. Check official marine forecasts, warnings, local observations and broadcasts immediately before departure and repeatedly during the voyage. Treat a source-age, degraded-coverage or fallback notice as a reason for more caution, not as an interface detail.

5. Boat data and draft

A boat profile may come from a manufacturer, charter operator, importer, user or other source and may not match the actual vessel, its loading, equipment or modifications. Physically verify at least the vessel identity, dimensions, draft and air draft; fuel, water, batteries and engine; navigation lights and instruments; anchors, chain, rode, markings and windlass; life-saving, fire and distress equipment; steering and emergency steering; radio and emergency contact arrangements; and known defects and charter-company notices. Never use a database value as the sole basis for entering shallow water, passing under an obstruction or calculating anchor scope.

6. Anchor watch limitations

6.1 A supplementary alarm only

The anchor watch is a convenience and risk-reduction aid. It does not keep a legal or practical anchor watch and cannot guarantee detection of dragging, wind shift, GPS drift, collision, swing into danger, mooring failure or grounding.

6.2 Technical dependencies

Its performance depends on a correct anchor position and radius; GNSS reception and accuracy; the phone or tablet hardware; operating-system background execution and battery optimisation; location and notification permissions; battery level, charging, temperature and device stability; sound volume, focus, silent mode and connected audio; network connectivity for remote sharing; browser and web-app push support; email-provider and recipient filtering; and the user's response. The app can raise a false alarm or fail to alarm. GNSS error can be significant near cliffs, structures, masts, enclosed cabins or interference.

6.3 The onboard device is primary

The device that stays on board with the skipper is the primary alarm device. Keep it powered, positioned for reliable GNSS reception, audible and monitored. Do not rely on a remote phone, watch, the Crew web app, email or another person's acknowledgement. Crew push and email fallback are supplementary; SMS is not used. A crew member's acknowledgement can quiet repeated notifications on that crew member's device for a limited time; it does not and cannot silence the onboard alarm.

6.4 Anchoring practice

The skipper must independently select a lawful and suitable anchorage, assess seabed and shelter, set adequate scope, test holding, monitor position and conditions, allow swinging room and keep an appropriate watch. Wind-biased or smart swing calculations are estimates, not guarantees. Never leave the vessel unattended because Mermaid shows a stable anchor position.

7. Anchorages, marinas and community information

Community observations are subjective and may be old, inaccurate or based on a different boat, weather, tide or local rule. A rating is not a safety certificate. Before relying on a location verify whether anchoring, mooring or entry is permitted; current depth and chart datum; underwater cables, protected areas and local restrictions; berth or buoy availability and condition; port opening, VHF channel and harbourmaster instructions; weather, sea state, tide and shelter for the current direction; and the actual fit for the vessel's draft, length and manoeuvrability.

8. Crew briefings and signatures

Mermaid guides a briefing and records photographs, acknowledgements or signatures. It does not know whether the briefing was accurate, complete or understood; whether equipment was demonstrated; whether language, disability, age or experience required adaptation; whether a responsible adult properly supervised a minor; or whether the briefing meets every legal, charter or insurance requirement. The skipper must give a practical, vessel-specific briefing and confirm understanding. A signature is evidence that an interaction occurred; it is not a waiver of rights, proof of competence or a release from negligence.

9. Inspections and evidence

An inspection workflow, camera guide, checklist or suggested inspection area can miss defects or create false positives. Inspect the actual vessel, use professional assistance where appropriate and report issues through the charter company's required channel. Photographs and checksums support a record but do not prove cause, timing, completeness or legal admissibility. Preserve original evidence and written acknowledgements when a dispute may arise.

10. Logbook and instruments

The logbook is kept on your device first and the server holds an optimised projection. It can be incomplete because of device loss, a permission change, a GNSS gap, a sync error or storage cleanup. Keep legally required logs through approved means. Do not connect Mermaid to instruments unless you are authorised and it is safe, and cross-check displayed values directly against the instrument and other sources.

11. Emergency use

Mermaid is not monitored as an emergency service and must not be used to call for rescue. In an emergency take the immediate action seamanship and the vessel's emergency plan require; use VHF channel 16, Digital Selective Calling, EPIRB or PLB, local maritime rescue channels or other distress equipment; call 112 in the EU where appropriate, recognising that marine radio or local rescue coordination may be faster and more suitable offshore; give your position and the nature of distress from reliable onboard sources; and never delay emergency action to troubleshoot Mermaid. A Mermaid notification, email or support request is not a distress call and may not be seen in time.

12. Device checklist before relying on a safety feature

Confirm that the app and operating system are supported and up to date; the correct boat, charter, units and time are selected; location and notification permissions are active; battery optimisation will not suspend the feature; the device is charged and on reliable power where appropriate; sound and vibration can be heard; offline data is downloaded and not stale; source age and coverage are acceptable; an independent navigation, weather and watch method is in use; and the crew understand that remote alerts are supplementary.

13. Reporting a safety issue

Report suspected wrong route geometry, depth, point-of-interest or boat data, a missed alarm or misleading output through the in-product report or to info@mermaid.navy. Include the feature, date and time, app version, device, location, source label and a description, but never delay immediate safety action to do so. We may preserve relevant logs and ask for diagnostic consent. A report does not guarantee immediate correction or publication.