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 blackfin snook
how to recognize it
Elongated, flattened-sided body, silvery, with a bluish or gray back and a dark lateral line. The outer third of the pelvic fin is usually black, and the membrane between the second and third anal spines is dark. Bent back, the second anal spine does not reach the base of the tail, and the pectoral fins are shorter than the pelvic fins; the anal fin has 7 rays. The armed snook and the yellowfin snook have a much thicker and longer second anal spine that reaches the tail; in the black snook and the white snook of the Pacific, the third dorsal spine is much longer than the first and second.
Also called: robalo-de-nadadeira-preta, róbalo aleta prieta, gualaje aleta manchada, Blackfin snook, Pacific blackfin
don't confuse with:
where found
open on the large mapWhere to look: Bays, estuaries and lower stretches of coastal rivers, including where dry river beds meet the sea; also in shallow coastal water.
Not found in Brazil. Eastern Pacific, from the southwest of Baja California Sur and the central Gulf of California (Mexico) to Ecuador, according to FishBase; STRI extends it to northern Peru. In Mexico it ranges from Bahía Magdalena and the southern gulf along the mainland coast to Guatemala, and is more abundant in the southern part of that range. FishBase lists Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia and Ecuador.
when to fish
best season
No seasonal study for this species. The app gives more weight to warmer water and to rivers with higher flow, from June to October, when fresh water reaches the river mouths.
best time of day
Dawn and dusk. No dedicated study. The app's estimate follows the snooks: more activity at dawn, dusk and at night, during tide changes.
what affects the blackfin snook
cold and cold fronts
Cold winter water reduces activity in the bays and at river mouths.
atmospheric pressure
Stable pressure helps; a front with strong wind shuts down fishing.
moon
Full-moon and new-moon tides move water at the mouths and in the channels.
rain
A rising, muddy river scatters the fish; clearing water afterwards is good.
water level
Falling river concentrates snook at mouths and channels.
noise
Sensitive to noise and to shadow on the water; arrive by oar or electric motor.
wind
Strong wind makes precise casting near roots and logs difficult.
tide
Ebb tide at river and lagoon mouths is usually the best.
depth
From 0.5 to 5 m, near logs, roots and current breaks.
how to fish
lures
- mid-water jerkbait, 7 to 10 cm
- silicone shad on a light jig head
- small stickbait at dawn
- streamer for fly fishing
natural baits
- live shrimp
- small live or dead baitfish
tip from an angler
Cast tight to the roots and along the edge of the channel and retrieve with pauses: the snook hits the bait that comes out of the shade carried by the current.
- rod
- 6' to 7', fast action, 6 to 14 lb
- spinning / baitcasting reel
- spinning reel 2000 to 3500
- line
- braided line 10 to 20 lb
- leader
- fluorocarbon 20 to 30 lb (the gill cover cuts)
- hook
- single hook no. 2 to 1/0; circle hook 1/0 to 2/0 on live bait
accessories
- alicate
- small boga-grip
- polarized glasses
catch and release
Hold it by the mouth with a wet hand, support the belly, and watch the sharp edge of the gill cover and the anal spines. Release it facing the current, only once it swims on its own.
rules for the blackfin snook
Rules change; before keeping or transporting fish, check with the state environmental agency.
Mexico: up to 5 per species and 10 saltwater fish per day
5 specimens of the species per angler per day, within the limit of 10 saltwater fish details
In recreational sport fishing in Mexican federal waters, each angler may keep up to 10 marine fish per day, no more than 5 of the same species. The black-finned snook is not among the species reserved for sport fishing (marlin, sailfish, swordfish, "sábalo o chiro," roosterfish and dorado, up to 50 nautical miles from shore, item 0.3 of the standard) and has no quota of its own. Fish over the limit go back alive (item 4.9.5), and sport-caught fish may not be sold. Anglers fishing from a boat need the permits of the Federal Duties Law; anglers fishing from shore do not (item 4.3).
Costa Rica: Incopesca sport fishing license
Personal Incopesca license, for people over 16confirm with the agency details
In the regulation of the Fisheries and Aquaculture Law (Decree 36782, of May 24, 2011), art. 69, sport fishing is authorized only for natural persons over 16, with a license issued by Incopesca; tourists, whether national or foreign, also need the license. Art. 68 limits the landing of large pelagics to 5 per trip, and art. 66 promotes catch and release, but the rule sets no quota for this species. The decree was later amended (Decree 39458), so confirm the current rule with Incopesca.
Panama: new sport fishing decree in force from Dec 10, 2026
Executive Decree No. 9 (Jun 10, 2026), in force from Dec 10, 2026confirm with the agency details
ARAP published Executive Decrees No. 9 and No. 10, of Jun 10, 2026, in the Official Gazette. The first regulates sport fishing throughout the territory; the second protects billfish (sailfish and marlins). Both take effect on Dec 10, 2026, after six months of adaptation. We did not verify the text: the press report gives no catch limits, sizes or license requirements. Before fishing in Panama, check with ARAP.
Colombia: AUNAP license and catch-and-release in sport fishing
Individual AUNAP license; catch-and-release guidanceconfirm with the agency details
AUNAP Resolution 0549 of 2022 sets the guidelines for sport fishing for recreational purposes in Colombia. Anyone fishing needs a permit: for a natural person, Colombian or foreign, it is a personal, non-transferable license (art. 6). The rule uses "capture and release" as guidance. We did not verify the daily limit or the minimum sizes by species: check with AUNAP before keeping any fish.
Conservation: Of least concern globally. Not listed in Mexico's NOM-059-SEMARNAT-2010. According to the 2021 fisheries management plan for Nayarit and southern Sinaloa, the snooks of the Mexican Pacific have no closed season or minimum size of their own.
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 = 0.00724, b = 3.05; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). It's an average: a fat or lean fish can vary by 10% to 20%.
more about the blackfin snook
Eastern Pacific snook: found from the southwest of Baja California Sur and the central Gulf of California to Ecuador (STRI extends it to northern Peru). Lives in bays, estuaries and the lower reaches of rivers; FishBase records adults in fresh water at 250 m of elevation and about 20 km from the coast, but it is most abundant in estuaries and also appears in coastal water. Eats fish and crustaceans, mainly shrimp and crabs. It reaches 65 cm and 3.2 kg; the IGFA world record, 3.2 kg, is from Costa Rica, 2002, according to a Mexican fish guide. In Mexico it is a small, uncommon snook that shows up in Los Cabos markets, where its white flesh is much prized.
Family: Centropomidae · predator
fun facts
- According to the Mexican guide consulted, in Los Cabos the small snooks of the genus are called paletas.
- According to FishBase, there are adults in fresh water at 250 m of elevation and about 20 km from the coast.
in the kitchen
White, firm flesh, considered excellent; fried, baked or in ceviche.
similar species
sources and references (10)
The season weights (months), time of day and sensitivities (cold, pressure, moon, wind, rain, tide, strong light, murky water and noise) are the app's editorial estimates, based on the literature below and on field experience of anglers and guides. They are not official data or measurements made for this species, and may vary by region and year. Closed seasons and legal rules appear in the rules section, with the standard and a link. The common size starts from FishBase's common length (30 cm), and the common weight is calculated from the length-weight relationship.
- scientific FishBase: Centropomus medius (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Centropomus mediusNames by country and language.
- scientific Robertson, D. R. & Allen, G. R. Shorefishes of the Eastern Pacific online information system. Smithsonian Tropical Research Institute: Centropomus mediusDescription, colors, size (up to 55.8 cm, with the IGFA record of 3.14 kg; we kept FishBase's 65 cm and 3.2 kg), depth and distribution in the eastern Pacific. Page checked on 13/10/2026.
- technical Mexican Fish (mexican-fish.com): ficha do Blackfin Snook (Centropomus medius)Independent guide to Mexican Pacific fishes, with photos of catches and the author's observations; not an official source. Page checked on 13/10/2026. It gives the distribution in Mexico, the IGFA record of 3.2 kg (Costa Rica, 2002) and how to tell it apart from the black snook and the white snook.
- official DOF: Modificação da NOM-017-PESC-1994, para regular a pesca deportivo-recreativa em águas de jurisdição federal do México (publicada em 25/11/2013)Species reserved for sport fishing (item 0.3), permits by mode (4.3), daily quotas at sea (4.9.1), catch and release (4.9.5), closed areas and seasons (4.10), and the ban on selling the fish (4.11). Text checked Oct 13, 2026. The DOF text carries only the signature date of Oct 14, 2013; the publication date (Nov 25, 2013) comes from Secretaría de Economía rules that cite the amendment.
- official NOM-059-SEMARNAT-2010 (DOF 30/12/2010) e modificação do Anexo Normativo III (DOF 14/11/2019): lista de espécies em risco do MéxicoSearch by scientific name in the two texts published in the DOF (the 2019 amendment is at https://dof.gob.mx/nota_detalle.php?codigo=5578808&fecha=14/11/2019): the species is not on the list. Checked Oct 13, 2026.
- official DOF 12/04/2021: Plano de Manejo Pesqueiro de robalo garabato, pargo colorado e curvinas em Marismas Nacionales, Nayarit e sul de SinaloaShows the state of regulation of the Mexican Pacific snooks: according to the plan, these fish have no specific regulation beyond the general conditions of the scale fishing permits, and the document contains no closed season or minimum size. We read sections 1 to 4; the final sections (existing management measures and action plan) were not read.
- official Decreto Executivo nº 36782-MINAET-MAG-MOPT-TUR-SP-S-MTSS, de 24/05/2011: Regulamento da Lei de Pesca e Aquicultura da Costa RicaChapter XVIII (sport fishing), arts. 66 to 69, and the requirements for the sport fishing card. Text checked Oct 13, 2026; the decree was amended later (Decree 39458) and the amendments were not read.
- press La Estrella de Panamá: Panamá implementa nuevas reglas para la pesca deportiva en diciembre (15/06/2026)Reports Executive Decrees No. 9 and No. 10 of ARAP, dated 10/06/2026, and their entry into force on 10/12/2026. The matter contains no catch limits, sizes or licenses; the text of the decrees was not read.
- official AUNAP (Colômbia): Resolução 0549 de 2022, lineamientos de ordenación pesquera para la pesca deportiva con fines recreativosWe confirmed the existence of the rule, the dates and the requirement for a personal card (art. 6, cited in an AUNAP notice). We did not read the articles on the daily quota and minimum sizes, so those figures are left out.
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: