Observation
A measurement at a place and time. Satellites can have cloud gaps; instruments have limits.
Origins of the data
Data Sources
& Attribution
A clearer picture begins
with knowing the source.
The ocean and weather programs behind the app and website reports. Source products, dates, coverage and limits.
Explore the sourcesData-service update
Ocean · Atmosphere · Seafloor
A field guide to the sources
One ocean.
Different kinds of information.
Some products begin with an instrument measurement. Others combine measurements into an analysis, estimate future conditions, or describe the seabed. Knowing the difference helps you interpret what a source can tell you.
Analysis
Measurements combined or reconstructed on a grid. A filled cell may be an estimate.
Forecast
A model estimate for a future time. Its issue time and valid time describe different things.
Reference layer
Chart, coastline or terrain context. Detail and revision schedules vary by source.
Website reports
Sources used by website reports
Your report names its sources and retains their dates. The report publication time is not the time every measurement was taken. Starting September 20, 2026, reports are scheduled once daily at 04:00 UTC. Until then, the noon and midnight Eastern schedule remains in place. A new issue can retain an older source date.
- Temperature
- NASA JPL MUR sea-surface temperature analysis.
- Water color
- OLCI and VIIRS products, where usable input is available. A reconstructed analysis is identified by its source, not as a new satellite observation.
- Currents
- NOAA AOML surface-current analysis.
- Weather
- MET Norway Locationforecast 2.0 point forecasts for wind and pressure. A point forecast does not describe every location inside your report area.
Check the source list in your selected report. An app layer listed below is not necessarily an available report field. Missing data does not establish that a feature is absent. Numeric samples do not establish complete coverage of your area.
Choose a destination report01 / Ocean
Satellite observations & analyses
The product matters as much as the satellite. These feeds include both observed and reconstructed information.
NASA / JPL · NOAA CoastWatch
Sea-surface temperature
MUR v4.1 combines satellite and in-water measurements into a daily, global sea-surface temperature analysis. It is a Level 4 foundation-temperature product; each cell is an analysed estimate, even where the map looks continuous.
- Product
- MUR-JPL-L4-GLOB-v4.1 ·
jplMURSST41 - Type / grid
- Analysis · 0.01° (about 1 km)
- Timing / extent
- Daily · global ocean; recent fields can be revised.
Read its limits. Grid spacing is not a guarantee of feature accuracy or a fresh observation in every cell. The field timestamp is the nominal analysis time. Publication and delivery occur later.
These data were provided by JPL under support by NASA MEaSUREs program.
Copernicus Sentinel-3 · NOAA CoastWatch / PolarWatch
Chlorophyll & ocean color
Ocean-color sensors measure reflected light. Processing estimates chlorophyll concentration from that signal. The source collection includes Sentinel-3A OLCI observations and a separate VIIRS DINEOF reconstruction.
Your water-color chart fills cloud gaps from the daily gap-filled analysis. Observed water and filled gaps use one solid, uniform surface. The pass date stays on screen and the header names the source.
- OLCI
noaacwS3AOLCIchlaDaily· Level 3 satellite product · daily, 0.0375° (about 4 km), global grid.- VIIRS DINEOF
noaacwNPPN20VIIRSDINEOFDaily· reconstructed analysis · daily, about 0.0833° (9 km), global grid.- Regional VIIRS
noaacwN21VIIRSchlaSectorUSDailyandnoaacwN20VIIRSchlaSectorUSDaily· satellite products · daily, 0.0075°, US-sector grid (approximately 0–60°N, 142.38–52.39°W).- Coverage
- Grid extent is not the extent of valid observations; clouds and quality flags leave gaps.
Read its limits. Clouds and retrieval quality can remove observed cells. DINEOF estimates missing values from spatial and temporal patterns; a reconstructed cell is not a new cloud-free measurement. NOAA identifies these products as experimental.
Contains modified Copernicus Sentinel data 2026. Ocean-color products distributed by NOAA CoastWatch and PolarWatch; originating sensor and product credits remain with their providers.
NOAA / NESDIS · NOAA AOML
Sea height & surface currents
Satellite radar altimeters provide sea-height measurements. Blended sea-level anomaly products supply broad ocean structure; NOAA AOML provides a separate geostrophic-current analysis derived from altimetry and climatology.
- Sea-level anomaly
noaacwBLENDEDsshDaily· daily blended analysis · 0.25° global grid, relative to the DTU15 mean sea surface.- Currents
miamicurrents· eastward and northward velocity · daily, 0.2° grid.- Current extent
- Approximately 64.7°S to 64.7°N.
Read its limits. Geostrophic flow is an estimate of a component of ocean circulation. It does not describe every tidal, coastal or wind-driven motion. A broad sea-height anomaly is not a direct temperature measurement.
Data courtesy of NOAA; Sentinel data courtesy of Copernicus Program; Generated using AVISO+ products.
University of South Florida · NOAA AOML
Sargassum / floating-algae index
The Alternate Floating Algae Index (AFAI) is a reflectance-based signal sensitive to floating material such as Sargassum. This feed contains seven-day cumulative fields from USF, distributed by NOAA AOML.
- Product
noaa_aoml_atlantic_oceanwatch_AFAI_7D- Type / grid
- Satellite-derived composite · 0.015° grid.
- Time / extent
- Seven-day accumulation · 0–38°N, 98–38°W.
Read its limits. A cumulative field combines different observation times. Sun glint, clouds and thick aerosols can saturate the signal. AFAI alone does not establish species, biomass or a current patch boundary.
The stated domain does not cover the U.S. Pacific coast or the entire Northeast. Even inside the domain, a destination may have partial or missing samples. A possible sargassum indication concerns a general area, not a confirmed weed line. Check whether your report actually lists this source.
02 / Atmosphere
Weather & tide forecasts
Forecasts describe a valid time and location. Their publication time is a separate part of the picture.
NOAA National Weather Service · MET Norway
Marine wind & pressure
NOAA NWS grid forecasts provide wind in supported US areas. MET Norway’s Locationforecast 2.0 supplies a global forecast source, including wind and pressure. NWS forecast grids are approximately 2.5 km. MET Norway’s global model is approximately 9 km, with regional differences; forecast intervals vary by service and region.
- NWS service
api.weather.gov· point lookup and forecast grid data.- MET service
Locationforecast 2.0 / compact· forecasts by coordinate.- Type / timing
- Forecast · use the issue time and the interval for which the forecast is valid.
Read its limits. Modelled winds may differ from local conditions, especially near shore or rapidly changing weather. Service coverage and delivery are not guaranteed.
Based on data from MET Norway, licensed under CC BY 4.0. BlueWater Marlin selects forecast intervals, converts units and presents derived displays; these are not MET Norway’s original presentation. NWS-sourced government information is not claimed as BlueWater Marlin copyright.
NOAA CO-OPS
Tide predictions
The Center for Operational Oceanographic Products and Services publishes station-based predictions of high and low water. The requested product is predictions, with a high/low interval.
- Service
- CO-OPS Data API and station metadata API.
- Type / coverage
- Tide prediction · locations in the NOAA prediction-station network.
Read its limits. A nearby station does not establish the tide at an offshore location. Prediction heights depend on the stated vertical datum; wind and pressure can affect actual water levels.
03 / Seafloor & coast
Charts, depth & coastlines
Reference layers give geographic context. A detailed-looking map may include modelled terrain, generalized coastlines and survey data of different ages.
GEBCO · NOAA NCEI · Scripps / UC San Diego
Bathymetry & terrain
- GEBCO 2026
- Global terrain and shaded relief · 15 arc-second grid. Product & attribution · Terms of use.
- ETOPO 2022
- NOAA global relief model ·
ETOPO_2022_v1_15s, 15 arc-second grid. Product record · Dataset citation. - SRTM30+ v11
- Global topography and bathymetry reference model ·
srtm30plus_LonPM180, 30 arc-second grid. Source & documentation · Dataset license.
Read their limits. These are reference models, with inputs from different surveys and estimation methods. Grid spacing does not establish the density of actual depth measurements. Vertical datums may differ. GEBCO must not be used for navigation or safety at sea.
SRTM30+ has separate commercial-use terms: its distributed license directs commercial users to UC San Diego Technology Transfer. Attribution on this page does not itself grant permission to use a dataset.
GEBCO Bathymetric Compilation Group 2026 (2026). The GEBCO_2026 Grid — a continuous terrain model for oceans and land at 15 arc-second intervals. NERC EDS British Oceanographic Data Centre NOC. doi:10.5285/4f68d5c7-45eb-f999-e063-7086abc036fa.
EMODnet Bathymetry Consortium
European depth contours
The app’s European depth-contour configuration uses emodnet:contours through the EMODnet Bathymetry Web Feature Service. This is a reference layer, not a weather forecast or a source for the U.S. destination reports. Survey age and compilation detail vary; contours do not establish safe water.
Credit: EMODnet Bathymetry Consortium and the contributing data originators identified in the service metadata. The EMODnet data product is owned by the European Union and licensed under CC BY 4.0. The app selects viewport contours and converts elevation to positive depth. Consult the source metadata for originator credits and any additional restrictions.
NOAA Office of Coast Survey
Nautical chart context
The NOAACharts map service supplies nautical-chart imagery. ENC Direct to GIS (general, coastal and approach layers) supplies vector depth contours and soundings where supported. Coverage, compilation scale and revisions depend on the source. A third-party display does not replace current official nautical charts.
GSHHG · Natural Earth
Shoreline reference
GSHHG 2.3.7, by Paul Wessel and Walter H. F. Smith, supplies shoreline geography under the GNU Lesser General Public License, version 3. Natural Earth’s public-domain reference mapping is also acknowledged in the app’s credits. Generalization and source age limit coastline detail; these lines do not establish safe water or legal boundaries.
Apple
Base map
Apple Maps supplies base-map context through MapKit. Its content, regional availability and attribution are governed by Apple and its data providers. Apple’s map credits remain part of the map display.
04 / Attribution & useCredit where it belongs.
Credit where it belongs.
Limits kept in view.
Independent sources
BlueWater Marlin is published by Red Oak Media House, LLC. The organizations named here are independent data providers. Their inclusion does not imply affiliation, sponsorship, endorsement or approval of BlueWater Marlin. Provider names identify the origin of data; ownership and applicable rights remain with their respective holders.
Source terms and derived presentation
Each product remains subject to its provider’s terms, licenses, attribution requirements and disclaimers. Public access does not mean every product has the same license. Links above identify the relevant source records and terms. BlueWater Marlin’s selected areas, unit conversions, rendering and derived displays are its own presentation and must not be understood as original or official provider products.
Timing, coverage and uncertainty
Observation time, analysis time, forecast issue time, forecast valid time and download time are different. Source grids can include missing, reconstructed or revised values. Delivery, geographic coverage, continuity, accuracy and fitness for a particular purpose are not guaranteed. Provider specifications describe their products; they do not establish the accuracy of a BlueWater Marlin result. The sources listed here may vary with the layer, region and app version.
Corrections and further information
For a missing credit, changed source or documentation correction, contact support@bluewatermarlin.com. Please identify the product and relevant link. Information about network requests and personal data is provided separately in our Privacy Policy.
Data services updated September 18, 2026 · Reference register reviewed September 8, 2026Back to top