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 03:33
Santander — solo, off the rocks
DON'T GO
don't go · wave 2.5 m (occasionally up to ~5.1 m)
wave 2.5 mwind 10 km/hsurge pounding the rocksvisibility ~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.
Best at first light, before the northwest breeze gets up, and in autumn, with the water still around eighteen degrees and fewer people up at the lighthouse. Cantabria has no weekday closure. Night diving is banned all over Spain, from sunset to sunrise.
tide
The tide here is the Cantabrian one: about 4.2 to 4.5 metres on springs and close to five at the extremes. At low water the slabs at the foot of the cliff come out and show you where to get in; at high water that same ledge is gone and the only way out is a swim back to the cove.
shelter
The Cabo Mayor lighthouse point faces north-northwest (340°) with nothing in front of it: the whole arc from 300° to 40° comes in clean, and the worst heading is the 325° northwest. Only a southerly or southwesterly land breeze flattens the sea under the cliff.
conditions
On flat summer days you get five to eight metres over the cape's rock. What ruins it is the northerly ground swell: two days of long waves and the water fills with sand torn off the Sardinero beaches. With a northwest wind it is not worth the drive.
hazard
The cape sits at the mouth of Santander bay: ferries and fishing boats go past, so the clearly visible red or orange buoy is not decoration (Decreto 45/2002, art. 8) and you must stay 300 metres from working professional boats. Add galerna squalls and swell washing the cliff base.
access
Climbing down the cliff from the lighthouse car park is awkward and the rock is loose; the comfortable entry is the Molinucos cove to the east, then a couple of hundred metres of swimming out to the point. With any surf do not try to get out over the slabs — swim back to the sand.
Rocky bottom below the lighthouse; sea bass and pollack, exposed to the NW, entry off the rocks.
In July and August the cove is a busy bathing beach: come at dawn or leave it for September and October, when the water is still mild and the sand is empty. In Cantabria any day of the week is allowed, but only between sunrise and sunset.
tide
With a range well over four metres the cove changes face: at low water twice as much sand appears and the ledges at both ends are exposed, while at high water they are under the sea. Getting in and out is easy at half tide; on a spring high the sand nearly vanishes.
shelter
The Mataleñas cove is tucked between Cabo Menor and the golf course, and that block of land takes a good deal of the west out. What does come straight in is north and northeast: with sea from the first quadrant the cove breaks and there is nowhere to hide.
conditions
The bottom is mixed: sand in the middle of the cove and rock towards the Cabo Menor point, and that is where you can see. After any pounding the sand stays in suspension a couple of days and you are down to three metres; with flat sea and sun you clear six easily.
hazard
The Mataleñas cliffs drop stones, so do not stand at the foot of the wall. In season there are swimmers: stay well away from the buoyed bathing area and carry the red or orange float, which is compulsory here. The catch limit is five kilos per licence per day.
access
You park up top, by the viewpoint and the golf course, and go down the concrete staircase to the sand. You walk in from the beach and swim a hundred and fifty to two hundred metres out to the rocky spur of Cabo Menor. The way out is the same staircase; there is no other.
Mataleñas cove and rocky ground; semi-sheltered from the W, mixed bottom.
Good window: sunrise under a high with less than half a metre of sea, and above all September and October, when the Pas runs clear and the water stays mild. In winter there are good days, but few, and you have to watch the forecast daily.
tide
Covachos is pure tide: the sand tongue that joins the beach to the islet only exists at low water, and with a range of over four metres it covers again fast. Work out your exit from the tide table or you end up on the far side with the wall behind you.
shelter
This stretch, between la Arnía and Covachos, faces north-northwest and is among the most exposed on the coast: the bad sector from 300° to 40° hits it head-on. Only the Covachos islet makes a little shadow with an easterly wind, and nothing else.
conditions
Over the rock ledges visibility is reasonable in calm weather, but the mouth of the Pas, just west of here, stains the water brown for days after real rain. You need a long anticyclonic spell: with a metre and a half of ground swell you cannot see the tip of your gun.
hazard
The descent path is eroded and the cliff edge crumbles; there have been rescues here. Current forms around the islet on the ebb and there is nobody to call. You are next to the Liencres dunes natural park: check what restrictions the area carries before you get in.
access
Park up top on the track out of Soto de la Marina and take a steep, unmaintained path down — grippy footwear helps. Get in over the sand beside the tombolo and come out at the same place; with any surf, forget about climbing the islet's rock.
Cliffs and sandy stretches to the west; rock bottom, very exposed to swell.
Langre is a surf beach: at weekends and in summer there are people in the water from early on, so the best window is midweek and very early, or autumn under a high. Remember that pollack is closed from 1 January to 30 April, and after that it is two fish and 42 cm.
tide
Here the tide really rules: on a spring low a huge sand platform appears and the slabs at the ends dry out, so half the approach is on foot. On a spring high the sand is swallowed against the cliff and the only way out is the staircase.
shelter
Langre is a long beach under a thirty-metre cliff, wide open to north and northwest; the worst heading, 325°, comes in unobstructed. The point at the eastern end, towards Galizano, gives a little lee in westerly wind, and with a southerly off the land it goes flat as a plate.
conditions
The water only comes good after several days in a row of calm sea and no rain; with sand lifted from the shorebreak you are left with two or three metres. What there is to see is on the rocky ends, not in the middle of the beach, which is clean sand and little else.
hazard
The cliff sheds rock and the path along the top is eroded, so do not hug the wall. Out of season there is no lifeguard, and the northerly ground swell arrives without warning while the sea looks calm. The northwest galerna can be on top of you in minutes.
access
Leave the car in Langre village, by the viewpoint, and go down the long wooden and earth staircase. Get in over the sand at the eastern end and swim out to the rock; do not climb out over the slabs with any surf, they break on top and the stone is a grater.
Cliff and sand to the east; rock at both ends, exposed to 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.
Live cameras, map & reference
Cameras · live
Look at the water right now.
Check the cam BEFORE you leave. Foam, brown/green murk, or waves washing the entry rocks = No-go. At night/in fog the cam is useless — treat it as «unknown», NOT «green».
✓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 Santander
Where can I spearfish in Santander?
Santander has rock entry points such as Cabo Mayor, Cabo Menor / Mataleñas and Playa de Langre. Santander's open coast faces north-west from Cabo Mayor to Liencres. Below you'll find each spot (access, shelter and hazards) and today's forecast.
When is the best season in Santander?
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 Santander?
~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 Santander 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 Santander?
Yes — in Santander 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.
✓Cantabria: the spearfishing licence is issued by the Gobierno de Cantabria — the 2nd-class licence enables spearfishing (sede.cantabria.es).
✓Cantabria recognises issued by the State or other communities: in its waters they «have full validity» (Ley 1/2021, art. 27.7).
✓Cantabria: the right to spearfish comes with the 2nd-class licence (Decreto 45/2002, art. 3.b); only a harpoon, hand-held or mechanically propelled, is allowed (art. 7); the buoy is red or orange and clearly visible (art. 8). The cap is 5 kg per licence per day, and from a boat carrying more than five licences, no more than 25 kg per boat per day (art. 9.1). Selling the catch, autonomous diving equipment, fishing between sunset and sunrise, port and prohibited/reserved areas and taking cephalopods are all prohibited (art. 14). Barred within 100 m of beaches and other bathing places, a distance that rises to 250 m from May to October (art. 15.b).
⛔ 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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