Licence a zdroje

CoveGuard — Third-Party Licenses

This file documents third-party assets included in CoveGuard that require attribution under their respective open licenses.

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Noto Sans (assets/google_fonts/)

The typeface CoveGuard uses to typeset its PDF exports (the logbook and the charter handover protocol). Bundled DELIBERATELY rather than downloaded: with no signal the document fell back to Helvetica, which has no Czech letters, and every diacritic came out as a hollow box.

• Files: NotoSans-Regular.ttf, NotoSans-Bold.ttf (fetched from fonts.gstatic.com — the very files the printing package would otherwise download at runtime).
• Author: The Noto Project Authors (https://github.com/notofonts/latin-greek-cyrillic)
• Licence: SIL Open Font License 1.1 — the full text sits next to the font in assets/google_fonts/OFL.txt.
• What the licence requires: keep the copyright and licence text (met by that file), do not sell the font on its own, and rename it if it is ever MODIFIED. CoveGuard does not modify the font in any way.

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Knot Illustrations (assets/knots/)

Step-by-step knot illustrations guiding how each knot is tied. Sourced from Wikimedia Commons (each file under its own license — attribution shown in-app on every knot card and listed below) and from public-domain works. All files were resized / recompressed for the app (the bowline GIF scaled to 380 px and the figure-eight converted from WebM to a 340 px GIF, animation preserved); no other changes. Creative-Commons files remain under their respective licenses; ShareAlike modifications (resize / format conversion) stay under the same license.

CC BY-SA 2.5/3.0 and GFDL dual-licensed files (rolling hitch, anchor bend, alpine butterfly, constrictor) are used under their CC BY-SA component.

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IALA Buoy Photos (assets/buoys/)

Buoy photographs are sourced from Wikimedia Commons under Creative Commons licenses. All photos are used unmodified (thumbnails resized by Wikimedia CDN). Original sources and authors are listed below.

Licence summary

CoveGuard is distributed under a proprietary licence. The CC BY-SA photos are display assets only — they are not modified and distributed as standalone files. The IALA reference screen that displayed them was removed on 2026-06-27 (its unused data and credit string followed on 2026-09-23; the sea-marks reference now draws its own vector pictures). The photos are still bundled in the application package, so their attribution stays in this file.

Per-photo attribution

• port_hand_a.jpg
  • File: Port Hand Buoy in the approaches to Port Qasim (2), 07.06.2021.jpg
  • Author: Muhammad Siddique Baloch
  • License: CC BY-SA 4.0
  • Source: https://commons.wikimedia.org/wiki/File:Port_Hand_Buoy_in_the_approaches_to_Port_Qasim_(2),_07.06.2021.jpg
• starboard_hand_a.jpg
  • File: Starboard Hand Buoy in the approaches to Port Qasim, 07.06.2021.jpg
  • Author: Muhammad Siddique Baloch
  • License: CC BY-SA 4.0
  • Source: https://commons.wikimedia.org/wiki/File:Starboard_Hand_Buoy_in_the_approaches_to_Port_Qasim,_07.06.2021.jpg
• north_cardinal.jpg
  • File: Sconce north cardinal buoy — geograph.org.uk — 3465306.jpg
  • Author: David Dixon / geograph.org.uk
  • License: CC BY-SA 2.0
  • Source: https://commons.wikimedia.org/wiki/File:Sconce_north_cardinal_buoy_-_geograph.org.uk_-_3465306.jpg
• south_cardinal.jpg
  • File: The "Egilsay Graand" South cardinal buoy — geograph.org.uk — 1885220.jpg
  • Author: Walter Baxter / geograph.org.uk
  • License: CC BY-SA 2.0
  • Source: https://commons.wikimedia.org/wiki/File:The_%22Egilsay_Graand%22_South_cardinal_buoy_-_geograph.org.uk_-_1885220.jpg
• east_cardinal.jpg
  • File: NE Shingles east cardinal buoy — geograph.org.uk — 3465286.jpg
  • Author: David Dixon / geograph.org.uk
  • License: CC BY-SA 2.0
  • Source: https://commons.wikimedia.org/wiki/File:NE_Shingles_east_cardinal_buoy_-_geograph.org.uk_-_3465286.jpg
• west_cardinal.jpg
  • File: West Bramble cardinal buoy — geograph.org.uk — 1937854.jpg
  • Author: Peter Facey / geograph.org.uk
  • License: CC BY-SA 2.0
  • Source: https://commons.wikimedia.org/wiki/File:West_Bramble_cardinal_buoy_-_geograph.org.uk_-_1937854.jpg
• safe_water_fairway.jpg
  • File: Munlochy Shoal "Safe Water" Navigation Buoy — geograph.org.uk — 1195631.jpg
  • Author: geograph.org.uk contributor
  • License: CC BY-SA 2.0
  • Source: https://commons.wikimedia.org/wiki/File:Munlochy_Shoal_%22Safe_Water%22_Navigation_Buoy_-_geograph.org.uk_-_1195631.jpg
• isolated_danger.jpg
  • File: Cardinal marks.jpg
  • License: CC BY-SA 3.0
  • Source: https://commons.wikimedia.org/wiki/File:Cardinal_marks.jpg
• special_mark.jpg
  • File: Nauticus buoy march 2009.JPG
  • License: Public domain
  • Source: https://commons.wikimedia.org/wiki/File:Nauticus_buoy_march_2009.JPG
• new_danger_emergency_wreck.jpg
  • File: Cardinal buoys waiting for deployment on Phares et Balises parking.jpg
  • License: CC0 1.0 Universal
  • Source: https://commons.wikimedia.org/wiki/File:Cardinal_buoys_waiting_for_deployment_on_Phares_et_Balises_parking.jpg
• port_hand_b.jpg
  • File: Small green lateral buoy (IALA region A).jpg
  • License: CC BY-SA 3.0
  • Source: https://commons.wikimedia.org/wiki/File:Small_green_lateral_buoy_(IALA_region_A).jpg
• starboard_hand_b.jpg
  • File: The Red and the Green — geograph.org.uk — 1475771.jpg
  • Author: geograph.org.uk contributor
  • License: CC BY-SA 2.0
  • Source: https://commons.wikimedia.org/wiki/File:The_Red_and_the_Green_-_geograph.org.uk_-_1475771.jpg

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DHMZ ALADIN-HR Weather Data

Wind forecast data for the Adriatic region is sourced from the ALADIN-HR numerical weather prediction model operated by the Državni hidrometeorološki zavod (DHMZ) — Croatian Meteorological and Hydrological Service.

CC BY 4.0 Attribution requirement

When wind forecast data from ALADIN-HR is displayed in CoveGuard, the following attribution is shown to the user:

Weather data: ALADIN-HR by Državni hidrometeorološki zavod (DHMZ) — CC BY 4.0

This attribution appears:

• In the wind/weather overlay layer on the map (attribution chip)
• In the About CoveGuard dialog (More → About)
• In this file

CC BY 4.0 license text: https://creativecommons.org/licenses/by/4.0/

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DHMZ station observations (measuring-station pins)

This is a different product from the ALADIN-HR section above. ALADIN-HR is a forecast model; this is the hourly observation feed from DHMZ's physical measuring stations. Same provider, same licence, different source and different obligations — which is why it gets its own entry instead of being folded into the paragraph above. Added 2026-09-10, when the observations first became visible to users as pins on the map; until then they were only used internally to score our own forecast.

CC BY 4.0 Attribution requirement

Attribution shown to the user:

DHMZ (Državni hidrometeorološki zavod) / CC BY 4.0

This attribution appears:

• In the sheet opened by tapping a measuring-station pin on the map
• In the station-versus-model row inside the anchorage detail sheet
• In the GET /weather/stations and GET /weather/verification API responses
• In this file

No values are altered. Wind is converted from m/s to whole knots for display and the compass direction is rendered as an arrow, but the underlying measurement is passed through unchanged, and a value the station did not report is shown as missing rather than as zero.

CC BY 4.0 license text: https://creativecommons.org/licenses/by/4.0/

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Other measuring-station sources (from 2026-10-15)

Each pin carries its own source and the station sheet shows that source's attribution (attribution per source in GET /weather/stations). Values are passed through unchanged (units converted for display only); a value the source did not report or flagged as not valid is shown as missing, never as zero. Licence research: docs/stanice/2026-10-15_soukrome_stanice_reserse.md.

ISPRA RMN (ispra_rmn, from 2026-10-16). Source: the public live map https://www.mareografico.it/it/mappa-interattiva.html (ISPRA publishes no API; one request every 10 minutes, no key or account). Licence: the site's legal notes (https://www.mareografico.it/it/notelegali.html, same text on https://www.mareografico.it/it/informazioni.html) release the numerical data under Creative Commons Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/it/legalcode) — "ISPRA li rilascia con licenza aperta CC-BY, così come sono" — and ask users to cite the network DOI 10.83182/ispra-rmn; the DataCite record of that DOI lists cc-by-4.0 as well. Recommended citation: Istituto Superiore per la Protezione e la Ricerca Ambientale, Nardone, G., & Picone, M. (2020). Rete Mareografica Nazionale [Data set]. ISPRA. https://doi.org/10.83182/ISPRA-RMN. The data are near-real-time raw data with automatic quality control only ("dati dinamici non validati"); CoveGuard says so in the attribution, does not use the ISPRA logo and does not suggest endorsement by ISPRA. Changes made: wind speed is converted from m/s to knots for display; a missing value (N/D) and a 0.0 m/s reading (suspect sensors in Bari and Palermo) are shown as missing, never as calm; ISPRA publishes no gusts, so none are shown. Research: docs/stanice/2026-10-16_ispra_rmn_reserse.md.

Meteocat XEMA (meteocat, from 2026-10-21). Source: the Generalitat de Catalunya open-data portal, dataset "Dades meteorològiques de la XEMA" (https://analisi.transparenciacatalunya.cat/resource/nzvn-apee.json, no key), which Meteocat itself recommended instead of its keyed API. The portal tags the dataset as a high-value dataset ("Dades d'Alt Valor – Meteorologia"); Commission Implementing Regulation (EU) 2023/138, Art. 4(3), requires such data to be made available under CC BY 4.0 or less restrictive terms. The dataset note "Propietat intel·lectual i industrial de METEOCAT" is honoured by naming Meteocat on every pin. Values used: mean wind speed and direction at 10 m and the strongest gust of each 30-minute interval; readings flagged invalid (N) are shown as missing. Changes made: m/s converted to knots for display; the interval is labelled with its end time. Notes: docs/stanice/2026-10-21_meteocat_xema.md.

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IALA Buoyage System

The sea-marks reference in the app (lib/features/seamarks/) describes the IALA Maritime Buoyage System (Region A) and the day shapes and lights of COLREG — published international standards. The meanings are facts of those standards; the texts are our own and the pictures are drawn by the app itself. No IALA text or figure is reproduced.

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Sentinel-2 cloudless satellite tile (assets/tiles/)

The onboarding demo (lib/features/onboarding/demos/) shows a real anchorage on a real satellite backdrop. Online it streams Esri World Imagery over the network (see the next section). Offline it falls back to a single tile that ships inside the APK, so the demo never ends up as an empty canvas on a boat with no signal.

CC BY 4.0 attribution requirement

Sentinel-2 cloudless 2024 by EOX IT Services GmbH (contains modified Copernicus Sentinel data 2024) — CC BY 4.0

CC BY 4.0 license text: https://creativecommons.org/licenses/by/4.0/

Where the user actually sees it (since 2026-08-12): the attribution is rendered in the bottom-left corner of the demo canvas (_AtribucePodkladu in lib/features/onboarding/demos/demo_bay_canvas.dart), and it names whichever basemap is on screen at that moment — the bundled Sentinel-2 tile when the device is offline, Esri when it is online. Before that date the attribution existed only in this file, which the user never opens; a licence notice nobody can see does not satisfy CC BY. The wording is deliberately not translated — it is the licensor's own, same rule as the weather-source line on the map (map_screen._wxModelCc).

The same product is already used for the offline satellite base map, which is downloaded to the device on demand rather than bundled; this section covers the one tile that is redistributed inside the application package.

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Esri World Imagery (streamed, never bundled)

The satellite base map — on the live map and in the onboarding demo — is served over the network from Esri World Imagery (https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/).

No Esri tile is shipped inside the application package, and the offline map download (OfflineRegionsService.tileLayers) pulls Sentinel-2, never Esri. Bulk caching or redistributing Esri imagery would breach their terms of service.

On-device caching — this section used to be wrong (fixed 2026-08-12)

Until 2026-08-12 the paragraph above also claimed "No Esri tile is cached in bulk or shipped inside the application package." The second half was true; the first half was not.

flutter_map 8.3.0 ships its own disk cache and it is enabled by default: NetworkTileImageProvider._loadImage falls back to BuiltInMapCachingProvider.getOrCreateInstance() whenever a NetworkTileProvider is built without an explicit cachingProvider, and every successfully fetched tile is written to <applicationCacheDirectory>/fm_cache (1 GB ceiling, filename = UUIDv5 of the tile URL). Nobody had turned that off for the satellite layer, so Esri tiles were accumulating on the device. Nothing in our code said "cache" — which is exactly why it went unnoticed.

What is switched off now, by passing cachingProvider: DisabledMapCachingProvider():

What is deliberately left cached — the switch is scoped, not blanket:

• the bundled Sentinel-2 tile is served by AssetTileProvider: no network, no cache, nothing to disable;
• Sentinel-2 fetched over the network is CC BY 4.0, which permits caching, so it keeps its cache;
• the carto / OSM basemaps are unaffected for the same reason.

Known, not yet closed — three further layers still stream Esri through the default (caching) provider. They were out of scope for the change above and are tracked by a test that fails if a fourth one appears (flutter_app/test/onboarding/podklad_cache_test.dart, group Z, case Z4):

• lib/features/map/widgets/weather_basemap_filter.dart — Esri World Hillshade (LandReliefLayer, live on the map)
• lib/features/map/widgets/anchor_zone_draw_screen.dart — Esri World Imagery
• lib/features/settings/screens/area_select_map_screen.dart — Esri Ocean Base

Scope of the verified claim — read this before quoting it. What measurement proves is narrow and deliberately so: the tutorial demo's satellite layer writes nothing to the disk cache. It is not a claim about the app as a whole, and the three layers listed directly above are the reason — one of them (LandReliefLayer) is live on the main map today. An earlier revision of this file ended with the unqualified sentence "no Esri tile reaches the disk cache", which contradicted its own preceding paragraph; that wording is withdrawn.

Within that scope the claim is verified by measurement, not by reading the code: the same test renders the demo's satellite layer against a local server and then inspects the cache directory, with a control case proving that a default NetworkTileProvider does write there.

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Weather radar — EUMETNET OPERA and Radar-DPC (Italy)

Observed precipitation on the radar layer is a composite of two sources:

Modifications: both inputs are resampled to a common Web Mercator grid, merged (the higher rain rate wins where both have data), colour-rendered into map tiles and, for OPERA only, advected for the +15/+30 min nowcast. Because the composite contains Radar-DPC data, the radar tiles produced by CoveGuard are licensed under CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). The attribution shown with the radar layer names both providers, both licences and the modification.

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Synoptic charts — Deutscher Wetterdienst (DWD)

The Synoptic chart (DWD) viewer (weather panel → “Synoptická mapa (DWD)”) shows original surface charts with fronts (including occlusions) drawn by meteorologists of the Deutscher Wetterdienst. CoveGuard does not redraw or compute the fronts.

“Re-use is permitted solely under the terms of the Creative Commons license BY 4.0 (CC BY 4.0) providing the source is duly acknowledged.”

Modifications: the analysis chart is resized from 4389 px to 2200 px width (same aspect ratio) and reduced to a 256-colour palette to save mobile data; the forecast charts are passed on unchanged. Nothing is drawn over the charts. Following DWD's attribution templates (https://www.dwd.de/EN/service/legal_notice/templates_dwd_as_source.html), the source and the licence are shown immediately below the chart, with “resized” (“zmenšeno”) for the analysis.

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Copernicus Marine Service — waves and tides

Wave forecasts (Mediterranean MEDSEA, produced by HCMR; Atlantic IBI; the Europe-wide wave overview from the global wave forecast produced by Météo-France) and tide, sea level and surface currents on the Atlantic coast (IBI) come from the E.U. Copernicus Marine Service.

Generated using E.U. Copernicus Marine Service Information.

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Weather model AROME — Météo-France

High-resolution forecasts for France, Corsica and the surrounding seas come from the AROME model of Météo-France (open data „Paquets AROME – Résolution 0,025°“ published on data.gouv.fr, downloaded anonymously from the public storage the dataset links to).

Modifications: fields are cropped to our sea areas, resampled to a 0.05° grid and blended with other models at the edge of their domains („Automaticky“ mode). Attribution in the app: „Météo-France (Licence Ouverte / Etalab 2.0)“.

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Posidonia meadows — Balearic Islands and Valencia (anchoring checks)

When you place an anchor in the Balearic Islands or off the Valencian coast, CoveGuard checks the spot against official seagrass maps:

Modifications: overlapping polygons are merged, boundaries are simplified (about 5 m tolerance) and slivers under 100 m² are dropped; the Valencian layer keeps Posidonia and Cymodocea as separate classes. Because the Balearic data are CC BY-SA, the Posidonia layer derived from them is licensed under CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0/). The anchoring check names the map and its licence next to the warning.

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No-anchoring zones — Balearic Islands and France (map layer “No anchoring”)

Modifications: Balearic zones are split into single polygons and rounded to 6 decimals; the layer derived from them is CC BY-SA. French zones are built from the coordinates in each order, closed along the coastline from OpenStreetMap (© OpenStreetMap contributors, ODbL); circles and 600 m bands are computed in a metric projection. One centre (zone F, Porquerolles) is not given as coordinates in the order and is derived from the islet outline — the app says so on the zone card. Orders n° 246/2020 (vessels of 24 m and more) and n° 110/2023 (vessels over 12 m) apply only above a boat length: the app shows and checks those zones only for boats they apply to, and to a boat with no length in its profile it shows them all. The rule texts on the cards are our own summaries; the orders themselves and local markings apply.

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Weather models — ICON-2I, ICON-EU, ECMWF, GFS and Open-Meteo

Besides ALADIN-HR (above) and AROME (below), the forecasts on the map come from these models. Each is downloaded from its provider's open-data service; fields are cropped to our sea areas, resampled to a common grid and, in the „Automaticky“ (Automatic) mode, blended with other models at the edge of their domains. The licence line under the map names every model on screen. Waves at a single chosen point are requested live from the Open-Meteo Marine API (last row).

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Lightning and satellite precipitation — EUMETSAT

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Weather warnings — MeteoAlarm

Official warnings of national weather services are relayed through MeteoAlarm (EUMETNET). Following the MeteoAlarm Terms and Conditions (point 5, version of 15 March 2024), the app names the national service that issued each warning (or “EUMETNET – MeteoAlarm” when information from more countries is combined), shows the time of issue (in local time) and links to https://www.meteoalarm.org. The warnings screen, whenever it lists a MeteoAlarm warning, shows this notice verbatim:

Time delays between this website and the www.meteoalarm.org website are possible. For the most up-to-date awareness information as published by the participating National Meteorological and Hydrological Services, please refer to www.meteoalarm.org.

Croatian warnings additionally come directly from DHMZ (CC BY 4.0).

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Seabed — EMODnet

Modifications: the safe-depth hatching is rendered directly from the EMODnet model without extrapolation — no-data cells near the coast are hatched as unsafe, no-data cells far from the coast stay transparent. The depths are indicative: the hatching layer says it does not replace a nautical chart, and the depth shown for a point asks you to check it with your sounder.

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Map data — OpenStreetMap and OpenSeaMap

Anchorages, buoys and marinas, places on the shore (restaurants, shops, fuel stations …), places with a story, ferry routes, park boundaries, lighthouses and the coastline outline come from OpenStreetMap.

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Places with a story — Wikipedia and Wikidata

Summaries of places in Discover (Objevuj) are mostly taken from Wikipedia articles, shortened and in part translated; for some places only the short Wikidata description is used, and the kind of place is partly taken from Wikidata. Curated entries and editor notes are our own text. Cards say “Source: Wikipedia + Wikidata” and link to the Wikipedia article where one exists.

Photos of places come from Wikimedia Commons under each file's own licence; the main photo of a place shows its author and licence. Our own illustrative photos are marked as such.

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Last updated: 2026-10-18