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
MeteoAlarm no dataupdated 21:23
Cagliari — solo, off the rocks
BORDERLINE
caution — solo off the rocks is risky, check on site · wind 13 km/h, gusts to 32 — caution
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.
The little cove under the Sella del Diavolo, 60 m off the shore: limestone, blocks fallen off the cliff and posidonia, 8-12 m. Entry from the flat rock on the west side of the cove, path down from Calamosca. Sea bream, saddled bream and octopus. A scirocco pushes swell in and dirties the water in half an hour.
On the west face of the Sant'Elia headland, 85 m off the lighthouse: a rock-and-sand rise over 6-10 m with thin posidonia. Entry from the rocks below the Calamosca road. The mistral builds here first and whitens the water; in a scirocco this side stays clean while Cala Fighera is in swell.
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.
min. 45 cm · RESTRICTED · max 1 grouper/day; BANNED in Sardegna & MPAs
Wreckfish
min. 45 cm · RESTRICTED · max 1 grouper/day; BANNED in Sardegna & MPAs
Brown meagre
2–15 m · — · twilight
min. 20 cm · RESTRICTED · protected in several MPAs · (verify against the norm in force)
Greater amberjack
min. 15 cm · Sardinia 60 cm · legal target · (verify against the norm in force)
Leerfish
min. 15 cm · Sardinia 60 cm · legal target
Grey mullet
0–2 m · — · —
min. 20 cm · Sardinia 25 cm · legal target
Red scorpionfish
3–20 m · — · daytime
min. 15 cm · legal target
Moray eel
1–15 m · — · twilight
min. 25 cm · Sardinia 60 cm · legal target
European conger
2–25 m · — · night
min. 25 cm · Sardinia 50 cm · legal target
Wrasse
min. 15 cm · legal target
Red mullet
min. 11 cm · legal target
Atlantic bonito
min. 25 cm · legal target
Common octopus
1–6 m · — · twilight
min. 450 g · legal target
Cuttlefish
legal target · (verify against the norm in force)
Law
✓NO paid licence, but a free MASAF REGISTRATION is mandatory (recreational sea-fishing declaration, online via SIAN/SPID, annual) — it is not a «licence».
✓Free-diving only: scuba/rebreather/hookah BANNED (art. 128-bis DPR 1639/68). The 16+ rule comes from a different act — D.Lgs 4/2012, art. 6 c. 5; handing a speargun to an under-16 is an offence (art. 13-octies c. 3 b, as replaced by L. 75/2026).
✓Night prohibited: spearfishing only from dawn to sunset (art. 129e DPR 1639/68).
✓Distances (art. 129 DPR 1639/68): ≥500 m from beaches with bathers; ≥100 m from fixed gear/set nets and from vessels anchored outside ports.
✓Buoy MANDATORY (art. 130 DPR 1639/68): float with a red flag bearing a white diagonal stripe, visible ≥300 m; the diver stays within 50 m of the buoy/support boat.
✓The speargun may not be kept armed out of the water (art. 131 DPR 1639/68) — load only when submerged.
✓The spearfisher may NOT gather corals, crustaceans or molluscs — the second paragraph of the same article (art. 128-bis DPR 1639/68; the same rule in D.M. 249/1987, art. 2). BUT cephalopods are EXCLUDED: octopus, cuttlefish and squid may be taken — the exception is kept in terms by the official guidance (circolare 6227201 of 23.07.1987). Mussels — up to 3 kg per person per day, but only with the Capo del Compartimento Marittimo's authorisation. The 5 kg daily cap counts EVERYTHING taken that day (D.Lgs 4/2012, art. 13-octies c. 4, as replaced by L. 75/2026).
✓You MAY carry a speargun and a breathing apparatus on the same boat — but at most ONE cylinder of up to 10 L per vessel, and using it to fish is prohibited (art. 128-ter DPR 1639/68). While you are down, at least one person must stay aboard ready to intervene, and there must be a rope long enough to recover the diver.
✓Sale of recreational catch is PROHIBITED (EU control regime, Reg. CE 1224/2009).
✓The 5 kg/person daily cap IS in force and carries a fine: €500–3 000 up to 10 kg, €2 000–12 000 up to 50 kg, €12 000–50 000 above (D.Lgs 4/2012, art. 13-octies c. 4, as replaced by Law 21 Apr 2026 no. 75). Exception: a single fish heavier than 5 kg. Recovery-plan species and bluefin tuna: +1/3 (c. 5).
✓Sardegna (autonomous): STRICTER minimum sizes (parenthetical in the species table: dentex 30, mullet 25, moray 60, conger 50, amberjack/leerfish 60 cm etc.) + FULL grouper (cernia) ban.
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 Cagliari
Where can I spearfish in Cagliari?
Cagliari has rock entry points such as Cala Fighera and Scoglio Sant'Elia. Eight kilometres of sand at the Poetto and one rock headland, Sant'Elia. Below you'll find each spot (access, shelter and hazards) and today's forecast.
When is the best season in Cagliari?
A long season, clear water almost all year. When the mistral (NW) shuts the west coast, you switch to the east side (Arbatax, Orosei); the south opens with a northerly. The peak is between late spring and autumn.
How cold is the water in Cagliari?
Warm and crystal: ~14–26 °C. A 3 mm suit in summer, 5 mm in the shoulder months. Among the best visibility in the Mediterranean, over granite and cliffs.
Is Cagliari good for a beginner?
Intermediate and up: granite and cliffs dropping into depth, crystal water. The mistral can make the west coast unworkable — switch to the east side. Know the many MPAs' boundaries. Buoy always.
Do I need a licence in Cagliari?
No — in Cagliari there is no paid licence; a free MASAF declaration is mandatory (the recreational sea-fishing communication, online via SIAN/SPID, renewed each year), which is not a «licence». Breath-hold only (no scuba), with a marker buoy and no selling the catch. See the guide.
✓Sardegna: seasonal urchin/crustacean closures and regional enforcement (Corpo Forestale) — but hand-collecting crustaceans is already nationally banned for the spearfisher.
⛔ Date mussels (Lithophaga lithophaga) — TOTAL BAN: fishing, possession, transport, sale (D.M. 16/10/1998; EU-protected). Never touch.
Rules change. Before heading out, check with MASAF (registration) and the Guardia Costiera / Capitaneria di Porto; Sicily and Sardegna add regional tightening.
Data partners
dive centres that send us real visibility readings