spearo sea-state engine: consensus of up to 6 models + satellite clarity (ZSD) + buoy-bias checks
Freshness
Re-read every hour, per coast
Compiled by the spearo sea-state engine · How it works →
The verdict comes from seven water factors and hard safety gates — not ten tabs. Go or stay.
How we score the water
Our own model
Our own forecast engine — not a third-party widget. It weighs these water factors into one go-or-stay verdict for this coast; the 0–10 dial is that verdict, read out as a number.
01
Swell & wave memory
Height, period and direction of the swell, plus the wake of recent storms — an old storm still stirs the water, and the engine remembers.
02
Wind & gusts
Speed and gusts, hour by hour — wind speed and an onshore push chop the surface and cut visibility.
03
Tide phase
Timing and range of the tide, calibrated per coast — big spring tides pull the verdict toward caution.
04
Water temperature
Sea-surface temperature — sharply cold water vetoes a green verdict.
05
Currents & outflow
Direction and drift of the current — it pushes you, and it drags turbid coastal water across where you dive.
06
Rain runoff & air clarity
Rain muddies the water inshore through land runoff, while fog and haze cut visibility at the surface.
07
Coast shape & exposure
How the coast faces the swell — a sheltered cove keeps the water clean; an exposed, head-on point takes a penalty.
Safety gates
Thunderstorm forecast — an instant red, no exceptions.
An official warning (MeteoAlarm / IPMA) — yellow, or red for the higher ranks.
Missing input data — a would-be green is capped to yellow rather than overstated.
Strong disagreement between forecast models — a green day is pulled back to yellow.
Night hours — where night spearfishing is banned by law the window is forced red; where it is legal (Australia outside NSW, New Zealand, South Africa) it is capped at yellow, never green.
It all folds into a single 0–10 score and one verdict: go or stay.
A forecast, not a guarantee — the sea has the last word.
Where to get in, where to hunt
Entry points with coordinates
Seabed relief — promising ground
This verdict — in your pocket. Open the app for the week's window.
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0 m
Surface
Wind, wave and the swell windows — when to go and the best hours.
spearo.app
no dataupdated 20:55
Bermeo — solo, off the rocks
DON'T GO
don't go · wave 2.8 m (occasionally up to ~5.7 m)
wave 2.8 mwind 8 km/hsurge pounding the rocksvisibility ~1 m
today, best window 06:00–09:00
fish · Visibility 1 m · Water 17.8°C
confidence low · verdict for the selected day
Whole week — tap a day. is driving swell right now.
›
Solo risk: carry a float · tell someone your plan and exit time · doubt = don't go. A model-based planner; the call is made on site.
Selected day
Windows, hours and the day's trends.
The day is picked above, in the hero. Here are that day's windows, the hour-by-hour map and the trends. Tap a window to break down the conditions.
Sunday · today2026-10-25
08:37–19:12 · full moon
▲ 04:00▼ 10:00▲ 16:00▼ 22:00mid-range tides · 3.7 m
Hours (06→20)
06
09
12
15
18
Day's trends
Tide-2.11 m
Wave3.10 m
Wind4 km/h
Water18 °C
fish activity: moon overhead 00:50 · high · moonset 07:45 · moderate · moon underfoot 13:10 · high · moonrise 18:30 · moderate
Conditions window06:00–09:00
don't go fish
Hs 2.84 m · roughperiod 9 swind 8→18surge 68.6viz 1 m
What's missing? Tell us what you'd like to see — new spots, species, data or features. We read everything.
Your best window — with you. Forecast in your pocket.
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−10 m
The water column
Visibility and what drives it — post-storm clearing, river plume, temperature and the thermocline.
What it is
A marine instrument, go / no-go for solo hunting.
spearo.app folds wind, wave, swell period, visibility, tides, water temperature and risk into a single verdict — go to the spot or not. It computes 7 days ahead from open marine models (Open-Meteo, IPMA), with no sign-up and no accounts. Built for solo spearfishing off the rocks, where any mistake costs dearly.
Now live: 3016 spots across 406 stretches of coast — mainland Portugal, Madeira and the Azores.
At spring low water, and the range here reaches 4.2-4.5 m, the rock platform of the arms is left dry and you can walk a good way before swimming. At high water the sand entry is short, but the shore break lands exactly where you are pulling your fins on.
shelter
It is a small cove west of Bermeo with rock arms on both sides that cut the easterly and westerly wind chop. What nothing here cuts is the northwest: with the 300-40° sector the sea walks in through the cove mouth and breaks on the sand. With south and southeast it goes flat as a plate.
conditions
The sand in the belly of the cove lifts at once, so after a northwest groundswell episode the water stays milky green for a day or two. In calm weather, over the rock arms and the weed, it reads reasonably well; you need two or three flat days in a row for it to be worth the drive.
hazard
Bathing area with people in summer: never shoot toward the shore and come out of the water with the gun unloaded, since carrying it loaded out of the water is banned. The Bermeo fleet passes close by and you must leave 300 m to professional boats at work. And night is out, sunset to sunrise.
access
Park up on the Bermeo-to-Bakio road and take the steps down to the sand. You swim out from the beach and head for the right- or left-hand rock arm; if the shore break is strong, come back over the sand and do not try to climb out on the rocks.
Rocky cove next to Bermeo; easy entry off the sand, semi-exposed.
Cantabrian tides are big: on springs the range runs 4.2-4.5 m and in extremes it brushes 5 m. Right off the cape tip the tidal stream is noticeable and doubles up when it meets northwest groundswell; the comfortable move is to get in near slack, with the water standing still.
shelter
The cape is the northernmost tip of Bizkaia with nothing in front of it: the 300-40° sector (NW-N-NE) rolls straight in and 320° is the worst bearing. It only works with land wind from south and southwest (180-240°), which flattens the surface; with a westerly the east face under the lighthouse gives some lee.
conditions
In a long calm with a southerly the water off the cape turns blue and you see the kelp forests from far off; one train of northwest groundswell is enough to lift particles off the weed and drop things to three or four metres. Over two metres of sea there is simply nothing to do here.
hazard
The galerna comes in from the northwest with no warning and leaves you with no way out here; the current at the tip can drag you off the reef. Bermeo is a working port: keep 300 m from professional boats at work, the buoy is compulsory and never more than 25 m from it. Night is banned all over Spain.
access
You get there on the Matxitxako lighthouse road, park up top and walk a long way down a path and slippery rock; in summer it is easier to come by boat from Bermeo. Always exit on the east face, in the lee: on the north tip there is no clean way out once there is any sea.
Rocky cape west of Bermeo; legendary sea-bass and sea-bream ground, very exposed to the NW.
The channel between Izaro and the mainland speeds up on the ebb and it shows badly on 4.2-4.5 m springs, which here come round twice a month. The sensible plan is to anchor at slack and work with the water standing; if it starts pulling, get back on the boat instead of swimming against it.
shelter
The islet stands alone in the estuary mouth and takes the north full on; the shelter is its south face, the one looking into the ría, which works as a lee in northwesterlies. With 320° up there is no good side at all, and the gap between Izaro and the coast chops up with any wind.
conditions
When the Oka plume is not out, the water around the islet is the clearest in the whole area and you can make out the rock drop-offs from the surface. A moderate groundswell is enough to turn it milky against the cliffs; the southeast face stays clean noticeably longer.
hazard
Izaro holds a bird colony and landing on it is restricted, so check first and do not go ashore on your own initiative. Add current, fishing boats running into Bermeo and the galerna, which here catches you far from everything. The buoy is compulsory and you stay within 25 m of it.
access
Boat only, out of Bermeo or Mundaka, fifteen to twenty minutes depending on the state of the sea. You work in the lee, with the boat on a controlled drift or anchored on the south face; enter and exit at the same point and be back aboard before the ebb kicks in.
Islet at the mouth of Mundaka; rocky drop-offs, boat access, sensitive to swell.
Everything hangs on the tide. On the ebb the channel current of the ría pulls hard seaward and the sandbanks dry out; with 4.2-4.5 m spring ranges the difference is enormous. Get in on the flood or near high slack, and get out before the water starts to drop.
shelter
You are inside the Urdaibai mouth on the west shore, and the land itself plus the Mundaka bar take away much of the northwest that flattens the cape. With southerly wind it goes completely still; what still gets in is long groundswell when it arrives big from 320°.
conditions
The Oka river rules here: a couple of days of rain and the brown plume comes down, so you cannot see the tip of your gun. The good stuff arrives after a dry week and on a flooding tide, when clean ocean water pushes up the channel; then the mixed rocky ground works well.
hazard
The Mundaka bar breaks when there is groundswell and is no place to be; there is constant boat traffic to Bermeo and Mundaka. River mouths are usually closed by regulation, so check it before you get in, and bear in mind that Urdaibai is a biosphere reserve with rules of its own.
access
You come in off the Mundaka road, where there are pull-outs and short descents to the rock on the west shore. Enter on the inner, sheltered side and do not cross into the channel: on the ebb it takes you, no argument. Exit where you entered, and if you doubt the current, stay out.
Rocky ground toward the Mundaka ría; mixed bottom, more sheltered from the NW.
SOLO is the biggest risk: underwater you can black out from lack of oxygen silently and fatally, with no one around. Solo is never truly «safe». Below are the best weather windows; carry a buoy, tell someone your plan and exit time, and any doubt — don't go.
One morning glance — and you know.
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≈
Surfacing
Cameras, map and reference — to hand as you come up.
✓Spearfishing licence mandatory; the AUTONOMOUS COMMUNITY issues it (not the State) and it is valid in the exterior waters of the whole coast. Free-diving only — scuba is banned (, art. 3).
✓Spearfishing catch may not be sold or traded — it is non-commercial fishing ().
✓Night prohibited: spearfishing only in daylight (sunset to sunrise not allowed) — , art. 16.d.
✓Marker buoy MANDATORY: mark your position with a clearly visible buoy and stay within 25 m of it — , art. 15.
✓Never keep the speargun loaded out of the water — , art. 16.a.
✓Keep at least 300 m from professional fishing vessels that are working — , art. 12.b.
✓The state act (, art. 16) bans, for spearfishing: a loaded gun out of the water; explosive/electric points and lamps (hand torches excepted); underwater scooters; night — from sunset to sunrise. Plus art. 12 b), d), e): 300 m from professional fishing vessels, light as an attractant, poisons/explosives. A ban in a PARTICULAR reserve, port or beach comes from that place's OWN instrument (the reserve's order, the autonomous community's rules, the port authority) — see the no-take zones on the map and your community's rules.
✓Min. sizes by ( + + EU 2019/1241): sea bass 42 cm (rec.) / 36 cm / 25 cm Mediterranean / 22 cm Canaries; gilthead bream 20 cm and white seabream 23 cm in the Mediterranean (EU 2019/1241); grouper 45 cm. See your zone's species card.
✓Only species in Annex I of may be taken; keeping, landing or transporting undersized specimens is prohibited.
✓The licence needs a medical fitness certificate for free-diving and civil-liability insurance (or a federative licence, which includes it). Mandatory in the Basque Country/Murcia/Asturias/Galicia; the federative licence covers it in Galicia/Balearics/Cantabria; the Canaries and Andalusia do NOT require it for the individual licence (a responsible health declaration). Minimum age generally 16 (14 in Andalusia).
Safety protocol
Sets: watch the wave trains ≥15 min before entering; Hmax ≈ 2×Hs, the wash can run 50 m past the foam line. A lull >10 min with period >12 s = a big set «overdue», do NOT enter; enter right after a full set passes and re-check at minute 30.
Exit FIRST: find your exit AND a backup before entering. On a rocky/boulder shore a 0.5 m rise in swell can make the exit impossible — getting pinned/unable to climb out is the main killer.
Headland rip: prominent points often have a permanent topographic rip regardless of the model — locate it, enter/exit on the windward side, never swim against it.
Cold: wetsuit per the SST chip; the first shiver = a metabolic surge and a drop in breath-hold → get out at the first steady shiver. Cap the session at 45–60 min below 15 °C.
Solo discipline: buoy up; tell someone the spot and exit time; conservative breath-hold (never push it in cold/murky/surfy water); visibility <3 m — don't enter.
Afternoon wind: on many coasts the wind builds from midday — plan to be out of the water by midday; the chop builds — get out.
UV 11:00–15:00 (UVI ≥6): sunscreen and cover up on the surface interval.
Solo is a fundamental risk (hypoxic blackout with no buddy). Any doubt = No-go.
FAQ — spearfishing in Bermeo
Where can I spearfish in Bermeo?
Bermeo has rock entry points such as Cabo Matxitxako, Aritzatxu and Portuondo (hacia Mundaka). Bermeo is a fishing town beside Cabo Matxitxako, a cape famous for sea bass and bream that catches the full NW sea. Below you'll find each spot (access, shelter and hazards) and today's forecast.
When is the best season in Bermeo?
Summer and early autumn are the windows — in winter the Bay of Biscay swell shuts the coast down. Tides are large (4 m+) and set up current, so pick a small-sea day with the tide in your favour.
How cold is the water in Bermeo?
~14–22 °C: cool, but it warms up in the summer window. A 5 mm suit at peak summer, 7 mm with a hood the rest of the year.
Is Bermeo good for a beginner?
Demanding: strong Biscay swell, big tides and exposed rock entries. It's for those who can already read the sea and pick the window well — not a coast to start on.
Do I need a licence in Bermeo?
Yes — in Bermeo you need a recreational sea-fishing licence (issued by the autonomous community); breath-hold only (no scuba), with a marker buoy and no night diving. See the guide.
✓There is no fixed national catch cap (, art. 5 delegates it to the communities); the standard is 5 kg/person/day, with 1 specimen allowed not to count (Canaries — Decreto 182/2004, art. 38.3; Murcia; Galicia; Basque Country). Protected species have per-piece quotas.
✓Only a harpoon is allowed — hand-held or mechanically propelled, with one or several points (, art. 14.1). Carrying spearfishing gear and underwater breathing equipment aboard AT THE SAME TIME is prohibited (art. 14.2) — an offence in itself, even if you dived on a breath hold.
✓Spain is not one jurisdiction. The licence is issued by a coastal autonomous community, and you must comply with the rules of the administration on whose littoral you are in the water: «debiendo cumplir la normativa establecida por la administración en cuyo litoral se realice la actividad» (, art. 13). Interior waters — inside the straight baselines: bays, coves, rías, the whole coastal strip — are the community's competence; exterior waters are the State's. So the age, the days of the week, the distances and the are found in your community's act, not in the state one.
✓Basque Country: the spearfishing licence is issued by the Basque Government — Gobierno Vasco (Eusko Jaurlaritza): Decreto 198/2000, platform, spearfishing valid 1 year.
✓Basque Country: spearfishing needs a SEPARATE licence (Decreto 198/2000, art. 4); it takes being 16, an official sports medical certificate of fitness for this very activity, and accident + civil-liability insurance (art. 7.3). The cap is 5 kg (art. 12.1). Barred within 250 m of properly delimited bathing or watersport areas (art. 14.3); orto to ocaso only (art. 16). Ports, docks, habitual anchorages, navigation channels and vessel-traffic zones are closed; and a biotope, a special-protection zone or an artificial reef closes spearfishing only when ITS OWN norm says so (art. 18).
⛔ Seahorses (Hippocampus) — protected (RPE).
Rules change and are REGIONAL. Before heading out, check with the competent autonomous community (licence) and the min-size table in force.
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