the right time
to be on the water
Choose the place and the species. The index, from 0 to 100, combines weather, sun, moon and tide with each fish's habits. Up to 28 days, with each day's confidence.
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hour by hour
slide your finger or mouse over the chart to see each hoursee hour-by-hour table
why this index at —?
choose the day
the fishing month at a glance
what's the best window for the crew?
Choose how many fishing days. We compare each stretch by its average index, discount days with a warning or closed season, and show the 3 best.
trend for the coming weeks
Line: the middle value of 31 simulations of the American GEFS model. Band: where 8 out of 10 fall. Narrow, firm trend; wide, high uncertainty.
everything about the longfin drum
how to recognize it
Oblong body, silvery blue, with an arched back and a pale belly. The flanks have dark stripes, the gill cavity is quite dark, and the edge of the preopercle, the cheekbone, is serrated. The second dorsal fin is long. The snout protrudes and the chin has a stiff barbel. It belongs to the same genus as the roncador (Umbrina roncador), which lives on part of the same coast.
Also called: corvina-de-nadadeira-longa, verrugato aleta larga, berrugata aleta larga, longfin croaker
don't confuse with:
We don't have tips on season, bait or technique for this species yet.
where found
open on the large mapWhere to look: Sandy bottoms of beaches and bays, also in tide pools along the coast.
Eastern Pacific, from Mexico to Ecuador, on sandy beaches, in bays and tide pools of Central America and the north of the South American coast.
rules for the longfin drum
Rules change; before keeping or transporting fish, check with the state environmental agency.
We found no species-specific rule beyond the region's general rules.
how much it weighs without taking it out of the water
estimated weight
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how we calculate
Length-weight relationship W = a·Lb (a = 0.00933, b = 3.07; FishBase (relação peso-comprimento bayesiana, estimativa pelo gênero e formato do corpo)). It's an average: a fat or lean fish can vary by 10% to 20%.
more about the longfin drum
The longfin croaker is a fish of the family Sciaenidae, the family of croakers and weakfishes. It has an oblong body, with an arched back, and grows to 40 cm, with a common size of 22 cm. It lives on sandy beaches, bays and tide pools, from Mexico to Ecuador. It feeds on crustaceans and worms from the bottom. Its snout protrudes, its mouth is small and turned downward, and its chin has a stiff barbel. It is considered a good table fish, sold fresh in markets, and its flesh is highly prized.
Family: Sciaenidae · predator
in the kitchen
Sold fresh in markets, and its flesh is highly prized.
similar species
sources and references (2)
Essential profile: size, length-weight, depth, countries and conservation come from FishBase and the cited regulations, and the texts were written from those sources. Season, time of day, sensitivities, technique and baits and lures are not included yet, because we did not find a good source for this species.
- scientific FishBase: Umbrina dorsalis (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Umbrina dorsalisNames by country and language.
how we calculatewhere each number comes from
The weather comes from three independent global models, cross-checked hour by hour: when they agree, confidence goes up; when they diverge, the band between them shows on the chart. Beyond 16 days, we use the GEFS ensemble of 31 simulations: if 20 of the 31 predict rain, the chance of rain is 65%. Sun and moon are calculated astronomically, with no uncertainty.
The index adds up, weighted for each species: time of day (species curve anchored to real sunrise and sunset), moon (transits, rise and set, phase), pressure (3 h trend and 24 h swing), water temperature (in rivers, estimated from air temperature; at sea, estimated by an ocean model), wind, rain, clouds, tide and the month in the species' cycle.
sources for this lookup
how accurate the forecast is
Accuracy measured in the reference project (4 regions, 93 days, forecast vs. observed): maximum temperature is off by 0.6 °C on average the next day and 1.7 °C at 7 days; rain of 5 mm or more is detected 76% of the time the next day and 57% at 7 days. Detection isn't everything: the false alarm rate isn't published here yet, and 93 days in 4 regions is still a small sample. We now also measure every day, at the app's destinations: