FISH FATHOM · CUSTOM BATHYMETRY

Blue Topo
Custom Relief.

See the shape.
Find your next mark.

NOAA BlueTopo depth data, finished with our custom color palette and sculpted slope illumination. A richer way to study the bottom before you make the run.

Explore Premium Discover the finish

Download available coverage. Take the detail offshore.

Actual custom relief showing detailed bottom texture offshore of Key Largo in the Florida Keys
ACTUAL GENERATED TILES Florida Keys · 25.18, −80.24

THE FISH FATHOM FINISH

Source depth.
Signature detail.

We customize how the seafloor is presented, preserving the underlying NOAA elevations. Every part of the finish has a job: separate depth, reveal transitions, and make the map easier to study.

01

A palette with purpose.

A fixed depth scale moves from warm shallows through green, cyan, blue, and indigo into the deep. The same base color represents the same source depth across the layer.

02

The shelf comes into focus.

Extra color separation from 50–200 feet helps you compare the depth bands around shelf edges, channels, and candidate fishing structure.

03

Small changes. Stronger definition.

Custom directional lighting applies 30× visual slope emphasis to the source terrain. Subtle transitions gain texture while the measured depth values stay unchanged.

COLOR YOU CAN READ

Depth, with distinction.

Base palette stops in feet below the source datum. Illumination brightens and darkens these colors to show slope texture; shadows alone do not tell you depth.

0ft
50ft
75ft
100ft
125ft
150ft
175ft
200ft
500ft
12,000+ft

CRAFTED FROM THE SOURCE

A considered finish.
An honest foundation.

Our rendering works from native NOAA BlueTopo elevation samples, converts depth to feet, and prepares map-ready imagery for offline use. Land and missing data remain transparent so the layer sits cleanly over your map.

Directional illumination is tuned in the generated imagery. The Florida Keys example reveals the fine texture in the published bottom data. Coverage and available detail depend on NOAA’s published source data; saved downloads need a refresh to pick up regenerated tiles.

Explore BlueTopo layers and coverage
A closer view of natural bottom texture in the actual generated Florida Keys relief
Florida Keys. Actual generated relief, cropped from NOAA BlueTopo source data. Custom illumination brings the bottom texture into focus.
Store proof

Explore the Fish Fathom experience.

See the wider app experience in product screenshots and store listings. Custom relief availability depends on source coverage and your platform’s eligible Premium entitlement.

Find us on Microsoft Store
Fish Fathom offshore conditions map layer in the mobile app
Map layers, conditions, routes, and saved spots are visible in the product.
Fish Fathom Captain Brad Power Prompts product screen
Captain Brad, diary context, saved spots, and planning prompts support the workflow.

Real app screens

Screenshots show map layers, Captain Brad, catch history, and offline prep instead of generic fishing art.

Public store pages

App Store, Google Play, and Microsoft Store pages stay one click away for current screenshots, version details, privacy labels, and reviews.

Planning companion

Fish Fathom supports trip decisions and is not a substitute for required navigation, regulations, safety gear, or local judgment.

YOUR NEXT RUN STARTS HERE

Make the bottom
part of your plan.

In Download Maps, select Blue Topo Custom Relief where coverage is available. Save your area, turn on the layer, and adjust opacity alongside your waypoints and routes. A signed-in eligible Premium account is required.

Download for iOS ↗View Premium access ↗

Premium from $5.99/mo or $44.99/yr.

BlueTopo is planning context, not a navigation chart. Depths are relative to the source datum, not current water clearance. Use official charts and current conditions.