Effective date: April 20, 2026

Disclaimer & Acknowledgements

Disclaimer

ChartNav is to be considered an aid for informational and leisure purposes only. It can contain errors and cannot substitute the official government charts and notices to mariners, which remain the only authoritative sources for safe navigation. Any use of ChartNav for navigation, safety, or operational decisions is done at the User's own discretion and risk.

ChartNav displays data derived from publicly broadcast AIS (Automatic Identification System) radio transmissions and from official governmental, hydrographic, and meteorological sources. Although the Owner strives to present information accurately, the data may contain inaccuracies, latency, omissions, or out-of-date material; may have been altered during format conversion; and may not reflect the latest corrections issued by the originating authorities. The Service is not a certified navigation system, does not comply with the performance standards required of ECDIS or other SOLAS-mandated navigation equipment, and must not be used as the sole basis for navigational or safety-of-life decisions.

Vessel positions displayed on ChartNav are transmitted by the vessels themselves over open VHF channels. Such positions may be delayed, absent, incorrect, or — in some cases — deliberately falsified. Static information such as vessel name, dimensions, cargo, and destination is entered by each vessel's operator and the Owner cannot verify its accuracy. Weather, radar, tide, current, and similar overlays are provided by third-party data sources and carry inherent uncertainty; predictions are models, not measurements.

The User assumes sole responsibility for the prudent and lawful use of ChartNav and for verifying any information obtained from it against official, up-to-date, and authoritative sources before making any decision that may affect safety, property, or compliance.

Acknowledgements

ChartNav integrates data and software provided by the following organizations and projects. Use of such data and software is subject to the respective terms and attribution requirements of each provider. Trademarks and names belong to their respective owners.

Automatic Identification System (AIS)

AIS transmissions are public radio broadcasts issued by vessels in accordance with International Maritime Organization (IMO) Resolution MSC.74(69) and the International Telecommunication Union (ITU) Radio Regulations, including Recommendation ITU-R M.1371. ChartNav receives and processes these public broadcasts and claims no proprietary right to the AIS data itself. The Owner is not affiliated with the IMO, the ITU, or any flag-state administration.

NOAA — National Oceanic and Atmospheric Administration

ChartNav uses data and services provided by NOAA and its constituent offices, including but not limited to:

NOAA Office of Coast Survey — Electronic Navigational Chart (ENC) data accessed through charts.noaa.gov and the ENC Online MapServer (Maritime Chart Service). This product has been produced from NOAA ENC® data and has not been verified or approved by NOAA for navigational use. Users of this product are advised that the official NOAA ENC® itself should be consulted for the most up-to-date information relating to maritime safety.
National Weather Service (NWS) — active watches, warnings, advisories, Local Storm Reports, Dense Fog Advisories, and related hazardous-weather data obtained through api.weather.gov and related services.
NEXRAD / MRMS — weather-radar Level II/III products and Multi-Radar Multi-Sensor composites. The color palette used by ChartNav follows conventions of NWS RIDGE and comparable public tools.
NOAA CO-OPS — Center for Operational Oceanographic Products and Services — tide and current predictions, water levels, and station metadata obtained through the CO-OPS Data API (api.tidesandcurrents.noaa.gov) and the MDAPI Web API.
NDBC — National Data Buoy Center — buoy station metadata and real-time meteorological/oceanographic observations obtained through www.ndbc.noaa.gov.
NOAA GOES-R Series — geostationary satellite imagery produced by NOAA and distributed via cooperative partners such as SSEC/CIMSS at the University of Wisconsin–Madison.

NOAA data is made available as a public service of the U.S. Government. The U.S. Government, NOAA, NWS, and their respective agencies make no warranty, expressed or implied, regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. NOAA data in ChartNav has not been verified by any of these agencies and may not meet national or international requirements for navigation.

U.S. Army Corps of Engineers (USACE)

Where ChartNav displays hydrographic survey data originating with the U.S. Army Corps of Engineers, that data is provided for general information only. It cannot be relied upon for any purpose and is not intended for use as a navigation aid. Hydrographic surveys are accurate only at the time they are measured and are subject to equipment tolerances and the natural variability of the waterway.

mPING — Meteorological Phenomena Identification Near the Ground

Citizen-science weather observations are provided by the mPING project operated by the National Severe Storms Laboratory (NSSL), the University of Oklahoma, and the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS).

Iowa Environmental Mesonet

Spotter reports and related mesoscale observations are obtained from the Iowa Environmental Mesonet operated by Iowa State University. ChartNav gratefully acknowledges the IEM's role in aggregating and redistributing National Weather Service data.

OpenStreetMap

Certain basemap and geographic reference data is © OpenStreetMap contributors and is made available under the Open Database License (ODbL). See www.openstreetmap.org/copyright for the full terms.

CARTO

Basemap raster tiles are served by CARTO (basemaps.cartocdn.com). Basemap styles are © CARTO, underlying data © OpenStreetMap contributors.

MapLibre GL JS

ChartNav uses MapLibre GL JS, an open-source fork of mapbox-gl-js originally released by Mapbox, Inc. MapLibre GL JS is distributed under the BSD 3-Clause License and mapbox-gl-js prior to its fork was distributed under the BSD 2-Clause License.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Wikimedia Commons & Wikipedia

Vessel photographs and certain reference information are retrieved from Wikimedia Commons and the English Wikipedia, operated by the Wikimedia Foundation. Individual files are released under a variety of free licenses (Creative Commons, GFDL, public domain); please consult the image's page on Wikimedia Commons for the specific license and attribution.

Google Fonts

Typefaces used in the ChartNav interface — including Inter and JetBrains Mono — are delivered by Google Fonts and licensed under the SIL Open Font License, Version 1.1. Trademarks of the typeface designers remain with their respective owners.

Open-source libraries delivered via CDN

ChartNav loads certain client-side libraries from public CDNs such as unpkg.com. These libraries, including MapLibre GL JS and related tooling, are licensed under permissive open-source licenses (BSD, MIT, or ISC) by their respective authors. ChartNav is not affiliated with unpkg or the authors of the libraries; their inclusion does not imply endorsement.

Hydrographic offices and chart authorities

Where ChartNav displays information derived from data published by national hydrographic offices and chart authorities — including NOAA Office of Coast Survey (USA), the Canadian Hydrographic Service (CHS), the UK Hydrographic Office (UKHO), the Instituto Idrografico della Marina (Italy), Bundesamt für Seeschifffahrt und Hydrographie (Germany), the Australian Hydrographic Office, and others — such information has been derived from publicly available material. None of these offices have verified the information in ChartNav, and none accept any liability whatsoever for its accuracy, up-to-datedness, or fitness for any particular purpose. Official charts and notices to mariners published by these authorities remain the only authoritative sources for safe navigation and should always be consulted.

Trademarks

AIS, ENC, ECDIS, NAVTEX, and other maritime-domain abbreviations are terms defined by the IMO or ITU. Product and company names mentioned on this page are trademarks or registered trademarks of their respective holders. Their use in this document is for identification and attribution purposes only and does not imply endorsement of or affiliation with ChartNav.

Contact

If you represent a data provider, rights-holder, or open-source project and would like to correct or update the attribution above, please contact legal@chartnav.ai.