Official sources first
Fish Fathom favors government, public, and traceable source context for map layers that affect trip-planning decisions.
Fish Fathom HomeData sources and coverage limits
Know what Fish Fathom uses before you trust a planning signal.
Fish Fathom combines NOAA bathymetry, CoastWatch sea-surface temperature, AIS-derived vessel history, public structure context, and your private fishing history. This page explains what each source is useful for and where the limits are.
Trust framework
Good fishing intelligence starts with source honesty.
A source-backed map layer should help narrow the plan without overstating certainty. The strongest read usually comes from comparing several signals and keeping the caveats visible.
Limits stay visible
Coverage, source age, cloud gaps, AIS gaps, and survey resolution can change the quality of any read. Those limits should remain part of the planning workflow.
Private context stays private
Your saved spots, routes, diary notes, catch logs, and Captain Brad conversations are account context, not a public fishing feed.
Official source inventory
What each source helps you decide.
These sources are useful because they make the plan more defensible. Fish Fathom does not guarantee catches, safe seas, legal access, or exact conditions on the water.
NOAA BlueTopo and National Bathymetric Source
BlueTopo and the National Bathymetric Source support higher-detail bathymetric context where published source coverage is available and Fish Fathom supports the area.
- Planning use
- Use it to compare depth changes, relief, contours, ledges, channels, and shoals before choosing a run.
- Coverage limit
- Coverage varies by region and source publication. It is planning context, not a replacement for official navigation, notices, or local seamanship.
NOAA NCEI multibeam and public bathymetry archives
NOAA NCEI bathymetry archives provide public survey context that helps explain why one area may have stronger bottom detail than another.
- Planning use
- Use the context to understand survey-backed bottom shape and why structure detail can be uneven across coastal and offshore areas.
- Coverage limit
- Survey age, density, instrument type, and metadata vary. A detailed-looking area is still not a legal, safety, or catch guarantee.
NOAA CoastWatch sea-surface temperature
Offshore Conditions uses NOAA-backed sea-surface temperature context so anglers can compare water edges with structure, routes, and saved marks.
- Planning use
- Use it as one signal for water-mass comparison before committing fuel to an offshore plan.
- Coverage limit
- Clouds, source age, composites, model interpolation, and fast-moving fronts can make SST stale or incomplete. It does not guarantee safe seas or fish.
MarineCadastre AIS vessel traffic
Commercial vessel track context comes from historical AIS-derived vessel movement data, converted into planning signals inside Fish Fathom.
- Planning use
- Use it to identify repeatable corridors, slow-down areas, and fleet behavior that may deserve more map research.
- Coverage limit
- AIS is historical and can have gaps. It does not prove a vessel was fishing, does not include every boat, and does not make a spot public or guaranteed.
NOAA public-data structure and hard-bottom context
Hard-bottom and structure markers combine confirmed NOAA seabed evidence with additional public-data-derived structure context where supported.
- Planning use
- Use it to prioritize areas for closer review alongside bathymetry, relief, waypoints, and current conditions.
- Coverage limit
- Substrate and structure context is uneven by region and source density. It should be treated as scouting evidence, not a live bottom survey.
Your private fishing history
Waypoints, routes, catch logs, diary notes, and Captain Brad prompts become the personal layer that makes planning more specific to your own trips.
- Planning use
- Use it to compare new plans with what you have already learned, saved, caught, skipped, or ruled out.
- Coverage limit
- Private history only helps when you keep it current. Fish Fathom is not built around publishing your spots to a public feed.
How to use source context
Turn source-backed evidence into a better trip plan.
Fish Fathom works best when source context is part of the pre-trip filter, not a promise that replaces judgment.
- Start with the public source layer that matches the decision: bottom shape, water temperature, vessel activity, or private trip history.
- Check the coverage or caveat language before you turn a map signal into a waypoint or route.
- Compare multiple signals instead of treating any one layer as a final answer.
- Verify navigation, regulations, weather, and safety with official tools before the boat leaves the dock.
Caveat answers
Source questions worth answering before the run.
Does Fish Fathom replace official nautical charts or safety tools?
No. Fish Fathom is a planning companion. Use official navigation, current regulations, weather products, safety gear, and local judgment before and during every trip.
Why does coverage vary by layer?
Each layer depends on different source data, publication timing, survey density, satellite availability, and Fish Fathom packaging support. Coverage varies by region and can change over time.
Do source-backed layers guarantee fish?
No. Source-backed layers help anglers compare evidence, but they do not guarantee catches, safe seas, legal access, or exact conditions on the water.
How is my private fishing data different from public source data?
Public sources help explain map context. Your waypoints, routes, diary notes, catch logs, and prompts are private account context and are not turned into a public spot feed.