From satellite to fishing boat — how the advisory is made
Seven data layers enter the portal, pass through a seven-stage processing chain, and leave as a single graded map with a plain-language reason attached to every zone. Nothing in the chain is hidden — every weight, threshold and safety rule is published below.
1Where the data comes from
Graded advisory map
Green, yellow and red cells over the Bangladesh maritime area.
Plain-language reasons
Every zone states why it received its grade, in words a fisher can check.
Safety warnings
Storm, sea-state, protected-area and shallow-water alerts carried alongside.
Offline package
Downloadable before departure for use with no signal at sea.
The index
How a fishing zone is decided
Five sub-indices are each normalised to a 0–100 scale, then combined with fixed published weights into one Fishing Opportunity Index. Because every term is separable, the portal can always say which signal carried a zone — and which one held it back.
Interactive
See the decision happen
This is the same scoring code the advisory service runs, executed live in your browser. Push the wave height past the safety limit and watch a high-scoring zone turn red.
Try the decision engine yourself
Move the sliders and watch the score, the grade and the safety rules respond live.
A sharp temperature break over a steep drop-off in calm weather.
Ocean conditions
How sharp the temperature break is — the single strongest signal.
Above about 8 mg/m³ the water is usually turbid river outflow, and the score falls again.
Preferred band 25–180 m.
Target species prefer 27.5–29 °C.
Safety conditions
Not advised at or above 2 m.
Not advised at or above 40 km/h.
Not advised at signal 3 or above.
Cloud hides the sea surface from the satellite and lowers confidence.
High fishing potential
Confidence: High
All safety checks passed
Sea state, storm signals, protected-area rules and depth are all within limits, so the grade comes from the score.
How the score was built
Grade boundaries: 70+ = high · 45–69 = moderate · below 45 = low. Any safety rule overrides all three.
Safety first
How the final advisory is decided
Safety screening runs outside the scoring engine and is evaluated first. A zone with a perfect index is still published as NOT ADVISED if the sea state, a storm signal, a protected-area rule or the charted depth says so.
Accuracy
What this advisory can and cannot tell you
The portal is a guide, not a guarantee. Being explicit about the limits is part of the design — every zone carries a confidence tag, and the reasons behind its grade are always visible.
Cloud limits the satellite view
Thermal and ocean-colour sensors cannot see through cloud. Cells built from fewer clear pixels are tagged Moderate or Low confidence instead of being presented as if they were fully observed.
Resolution sets the useful scale
A 0.2° cell is roughly 22 km across. The advisory points to a promising area of sea, not to an exact spot — and it is weakest close to the coast and inside river channels, where the global layers are coarsest.
Freshness matters
Satellite fields refresh daily; weather refreshes several times a day. Every zone shows when its inputs were acquired, so an old package downloaded before a long trip is never mistaken for live guidance.
Validation plan
In the pilot phase the index is calibrated against published potential-fishing-zone methodology for the Bay of Bengal. The next step is a catch-log feedback loop: logged catches from participating vessels are matched back to the zone grade that was in force, which turns the weights above from a reasoned starting point into values fitted to Bangladesh's own waters.
See the methodology applied on the live map
Every cell on the advisory map links back to the score breakdown shown here.