Sources:MeteoAlarm · Open-Meteo · Copernicus · Sentinel-2 — high confidence · data 12:38
Sources & confidence
Sources
MeteoAlarm · Open-Meteo · Copernicus · Sentinel-2
Method
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.
point your camera
0 m
Surface
Wind, wave and the swell windows — when to go and the best hours.
spearo.app
MeteoAlarm no dataupdated 12:38
Exposed coast — Hydra south & Bisti — solo, off the rocks
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.
point your camera
−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.
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.
point your camera
≈
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».
connecting to the stream…
Hydra — Hydra harbour, Saronic Gulf (meteocam.gr)meteocam.gr (Cybex) live — Hydra harbour, Saronic Gulf. Embedded via our proxy (the stream sends no CORS). Read the water and surf before you go.camera: meteocam ↗
National minimum sizes + a 150 g floor (in the table below); grouper 1/day. Spearfishing is closed all May (ΠΔ 373/1985).
In season now
white seabream
Diplodus sargus · 0–12 m · EU 1967/2006
common octopus
Octopus vulgaris · 0–15 m · weight ≥750 g
Minimum by weight: ≥750 g (ΠΔ 62/2024). Don't take egg-bearing females.
dusky grouper
Epinephelus marginatus · 8–35 m · EU 1967/2006
Grouper: max 1/day (shared genus-Epinephelus limit).
common dentex
Dentex dentex · 12–40 m · min 150 g
Premier reef target. No EU size — the 150 g minimum only. Ethical ≥40 cm (not law).
red porgy
Pagrus pagrus · 15–40 m · EU 1967/2006
gilthead seabream
Sparus aurata · 2–20 m · EU 1967/2006
European seabass
Dicentrarchus labrax · 0–15 m · EU 1967/2006
saddled seabream
Oblada melanura · 3–15 m · min 150 g
No EU size — only the 150 g minimum applies.
greater amberjack
Seriola dumerili · 5–30 m · min 150 g
No EU size — only the 150 g minimum applies.
leerfish / garrick
Lichia amia · 2–20 m · min 150 g
No EU size — only the 150 g minimum applies.
Mediterranean barracuda
Sphyraena viridensis · 3–25 m · min 150 g
No EU size — the 150 g minimum only. Histamine: bleed and chill at once.
flathead grey mullet
Mugil cephalus · 0–8 m · min 150 g
No EU size — only the 150 g minimum applies.
striped seabream
Lithognathus mormyrus · 2–15 m · EU 1967/2006
brown meagre / corb
Sciaena umbra · 5–30 m · EU 1967/2006
striped red mullet
Mullus surmuletus · 3–30 m · EU 1967/2006
white grouper
Epinephelus aeneus · 15–45 m · EU 1967/2006
Grouper: max 1/day (shared genus-Epinephelus limit).
goldblotch grouper
Epinephelus costae · 10–35 m · EU 1967/2006
Grouper: max 1/day (shared genus-Epinephelus limit).
wreckfish / stone bass
Polyprion americanus · 30–60 m · EU 1967/2006
Deep wreck species. Does NOT count toward the grouper limit (different genus). 45 cm — to verify.
Mediterranean parrotfish
Sparisoma cretense · 2–20 m · min 150 g
Eastern-Med delicacy (Crete/Dodecanese). No EU size — the 150 g minimum only.
devil firefish (lionfish)
Pterois miles · 5–40 m · invasive
⚠️ Invasive — removal encouraged, excellent flesh. Venomous spines: never grab bare-handed, cut the spines, treat a sting with hot water (>45 °C).
silver-cheeked toadfish
Lagocephalus sceleratus · 5–40 m · invasive
☠️ Invasive — kill, but DO NOT EAT: deadly toxin (TTX). Sale banned (Reg. 853/2004, Annex III Sect. VIII Ch. V(E)). Powerful beak bites — never string it live on a stringer.
rabbitfish
Siganus rivulatus / luridus · 2–20 m · invasive
Invasive — removal encouraged, edible and tasty. Venomous dorsal/anal/pelvic spines — remove carefully, treat a sting with hot water.
Law
✓⚠️ MAY — a TOTAL spearfishing ban for the whole month, every year (ΠΔ 373/1985, art. 3§1α). This is law in force, not a draft.
✓No licence required: the was abolished in 2014 (Ν. 4256/2014) — every standing prohibition stays in force all the same.
•Recreational-fisher registry (ΟΣΠΑ / Μητρώο Ερασιτεχνών Αλιέων): Reg. (EU) 2023/2842 obliges member states to register recreational fishing, and the Greek registry is described as being prepared. We found neither an act in force nor a working registry as of 08.2026 — not confirmed. Check gov.gr before you travel.
✓Age: 16+ (under-16 spearfishing is forbidden; ΠΔ 373/85, art. 3§1γ).
✓Daytime only: sunrise to sunset. Night is forbidden (ΠΔ 373/85, art. 3§1β).
✓Freediving only: scuba/any air-supply apparatus is banned — it may not even be carried aboard (ΠΔ 373/85, art. 3§2γ).
✓Distances: ≥200 m from bathers, harbours, moored vessels and marked nets; no hunting in fairways or harbour entrances/exits (ΠΔ 373/85, art. 3§1δ/ε).
✓Buoy MANDATORY: a yellow float + a yellow flag with a red diagonal stripe and the letters «Υ.Δ.», visible from ≥300 m; stay within 50 m of the buoy (ΠΔ 373/85, art. 3§3).
✓Limit: 5 kg/day (or one trophy heavier than the limit). Grouper (Epinephelus) — max 1/day, not banned (ΠΔ 373/85, art. 2§2).
✓Sale/trade of the recreational catch is prohibited (ΠΔ 373/85, art. 1§7).
✓Load the speargun only in the water — never keep it loaded out of the water (ΠΔ 373/85, art. 3§2β). Underwater light while hunting is forbidden (art. 3§2ζ).
✓Sea urchins — 20/day per person and 30/day per boat (ΠΔ 373/85, art. 2§2). Nets at any stage of the hunt are banned, and you may not take the catch out of somebody else's gear or nets (art. 3§2). Sponges and corals are off limits to the recreational fisher (art. 1§6).
✓Pneumatic and band guns are ALLOWED (a myth in English guides). Only spears with an explosive/chemical charge — — are banned (ΠΔ 373/85, art. 3§2δ).
Min. sizes: seabass 25 cm · gilthead 20 cm · white seabream 23 cm · grouper 45 cm · octopus 750 g (ΠΔ 62/2024). Any fish — not under 150 g (ΠΔ 373/85, art. 3§2στ). No-size species (dentex, amberjack, barracuda, parrotfish) — the 150 g minimum only. See the species card.
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 Hydra
Where can I spearfish in Hydra?
Hydra has rock entry points such as Bisti (Cape Bisti, W tip), Agios Nikolaos (S) and Mandraki (E of town). A steep rocky coast with quick deep drop-offs, the best grouper-on-the-edge terrain in the inner Saronic, and water clearer than Aegina or Poros (12–18 m). Below you'll find each spot (access, shelter and hazards) and today's forecast.
When is the best season in Hydra?
Long season, June to October (May is the national closed month). The sheltered Saronic opens on most calm mornings; peak is high summer.
How cold is the water in Hydra?
Warm mediterranean water (~24–26 °C in summer, ~15 °C in winter), tideless; clear over rock but murkier near Athens' shores.
Is Hydra good for a beginner?
Easy access and mostly sheltered water — a good place to start, with rocky capes and islets a short hop from the city.
Do I need a licence in Hydra?
No paid licence is needed in Hydra — the amateur one was abolished (Law 4256/2014), but a free ΟΣΠΑ registration is being introduced (check gov.gr). Breath-hold only (no scuba), a mandatory «Υ.Δ.» buoy, 16+, daytime only, and the whole of May is closed. See the guide.
Which fish can you spear in Hydra?
The species cards list 22 species with real presence in this basin; the strongest here are white seabream, common octopus, dusky grouper, common dentex, red porgy and gilthead seabream. Minimum sizes in Greece are NATIONAL, not local: white seabream 23 cm · dusky grouper 45 cm · red porgy 18 cm · gilthead seabream 20 cm · European seabass 25 cm · striped seabream 20 cm · brown meagre / corb 25 cm · common octopus 750 g. Species with no EU size carry the 150 g floor only. Grouper (Epinephelus) — max 1/day, not banned (ΠΔ 373/85, art. 2§2).
Is spearfishing banned in May in Hydra?
Yes. May is a TOTAL spearfishing ban for the whole month, every year, across Greece (ΠΔ 373/1985, art. 3§1α) — so in Hydra too. It is law in force, not a draft, and there is no local exemption. Plan June to April.
How many kilos of fish may I keep per day in Hydra?
The daily limit is 5 kg, or one trophy heavier than the limit (ΠΔ 373/85, art. 2§2). Grouper (Epinephelus) — max 1/day. Every fish must be at least 150 g (art. 3§2στ), and selling a recreational catch is prohibited (art. 1§7). The limit is national — in Hydra it is the same as everywhere in Greece.
✓Full ban on taking: Pinna nobilis (πίννα), corals and sponges (ΠΔ 373/85, art. 1§6 + Habitats Directive 92/43).
✓Invasives: taking the lionfish (λεοντόψαρο) is encouraged — ⚠️ venomous spines. The silver-cheeked toadfish (λαγοκέφαλος) ☠️ DO NOT EAT — deadly toxin (TTX), sale banned (Reg. 853/2004, Annex III Sect. VIII Ch. V(E)), it bites. The rabbitfish (γερμανός) is edible — venomous spines.
✓In ANY declared underwater archaeological site, and in the submerged historic sites, spearfishing is BANNED — the act names ψαροντούφεκο in so many words (ΚΥΑ ΥΠΠΟ/ΓΔΑΠΚ/ΑΡΧ/Α1/Φ41/11228/1865, ΦΕΚ 336/Β/2004, part Α §2 δ + part Β). It reaches the sites our map does not draw, too. Do not touch antiquities (Ν. 3028/2002). Map of the zones — the ENALIA geoportal (thalchor-2.ypen.gov.gr/layers/geonode:ENALIA).
•The national marine parks of Alonissos/N. Sporades and Zakynthos (Laganas): spearfishing is BANNED in the park. But Alonissos zone Β4 is not solid — ΦΕΚ 1741/Β/2011 reopened four stretches inside it (the N shore Αγ. Δημήτριος–Άκρο Απύθμενο, Μηλιά–Σπαρτίνες, όρμος Κλήμα on Περιστέρα, the Μεγάλος Αδελφός shore), while the same act creates the ΕΕΑΧ Περιστέρας, where fishing IS banned. Our layer paints the park whole, i.e. stricter than the act. Check the limits with the park authority.
•The Southern Kynouria/Arcadia diving park: Ν. 4688/2020 establishes underwater parks, but we have not read a spearfishing prohibition inside it in the act — we treat that as NOT PROVEN rather than as confirmed. The park's boundary is not on our map either (the act publishes no coordinates). Ask the Leonidio/Tyros λιμεναρχείο before you go.
•Local bans: on top of the national rules, every port authority issues its own (ΓΚΛ/ΕΚΛ and λιμενάρχης decisions). In the ΛΣ-ΕΛ.ΑΚΤ registry we counted ~163 of them that reach a speargun, across 48 ports — our map does NOT draw them. Check your own port: alieia.hcg.gr/prohibitions/local/local17.php.
•Locally STRICTER than the national rule: Corfu (Kerkyra) — from 01.04 to 31.10 spearfishing is banned within 200 m of the shore, even where nobody is swimming (απόφαση Λ/Χ Κέρκυρας 2141.1/2939/2024, ΦΕΚ Β΄3269/2024). In practice that closes shore entry on Corfu for the season. We read the act in the registry, not in the ΦΕΚ — confirm with the λιμεναρχείο.
•Locally STRICTER: Lefkada — 300 m instead of 200, and not only the speargun: ψαροντούφεκο, nets and longlines are banned within 300 m of those sea areas, beaches and shores of the port district THAT ARE USED BY BATHERS (απόφαση Λ/Χ Λευκάδας 2131.13/1477/2022, in its own words «όπου χρησιμοποιούνται από λουόμενους»). The act ran to 30.09.2022 and we found no extension; an expired act is not proof that the ban is gone. Ask the Lefkada λιμεναρχείο.
•Locally STRICTER: Symi — from 15.06 to 15.09 fishing BY ANY MEANS is banned within 200 m of beach areas and in inhabited coastal areas WHERE BATHERS ARE PRESENT OR GATHER (απόφαση Λ/Χ Σύμης 2131.13/882/2016). Separately, year-round: fishing by any means is banned inside the port and its sea zone, except line/rod fishing from land (ΓΚΛ Σύμης, art. 151, ΦΕΚ 362/Β/2004). The acts were copied from the registry, not checked against the ΦΕΚ.
•Locally: inside the ports of Lavrio and Kea spearfishing is banned across the WHOLE port water, not merely under the 200 m rule; separately, in front of the hotel beaches (ΓΚΛ Λαυρίου, art. 240, ΦΕΚ 460/Β/1978). The act was copied from the registry, not checked against the ΦΕΚ.
•Coming: two new national marine parks are being created (Ionian + South Cyclades, ~27,500 km²). NOT yet in force (ΠΔ under review, mid-2026). Once live — a trawl ban + a seasonal coastal closure 15.04–31.05; in the strict zones spearfishing will be banned. Check before the season.
⛔ Pinna nobilis (πίννα, fan mussel) — full ban on taking/killing (Habitats Dir. 92/43 Annex IV; critically endangered).
Rules change, and the local Λιμεναρχείο (port authority) may impose local restrictions. Before heading out, check the current rules and the declared archaeological zones (ENALIA).
Can I spearfish on scuba in Hydra?
No. Freediving only: scuba and any air-supply apparatus are banned — they may not even be carried aboard (ΠΔ 373/85, art. 3§2γ). In Hydra the rest of the national frame applies too: 16+, daytime only, ≥200 m from bathers, harbours, moored vessels and marked nets, and a mandatory «Υ.Δ.» buoy you stay within 50 m of. Pneumatic and band guns are allowed; only powerheads are banned.
