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The full spot briefing is part of the subscription: entry, bottom, hazards, tide window.
Open in the appToday — right on the edge — wave, wind and noticeable surge.
Sources & confidence
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.
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.
Safety gates
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
Leave your email — and the moment a window opens at Parnaíba, we'll send the go / no-go verdict. Email is all we need.
Every covered town has its own live forecast, cameras and entry points. Choose where you're diving.
What's missing? Tell us what you'd like to see — new spots, species, data or features. We read everything.
Wind, wave and the swell windows — when to go and the best hours.
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.
Visibility and what drives it — post-storm clearing, river plume, temperature and the thermocline.
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: 1391 spots across 205 stretches of coast — mainland Portugal, Madeira and the Azores.
See all spotsRelief and bottom type, tides, and the depths of each spot.
The models set the window. Whether you go in is read only at the water: count the sets, watch the surge on the entry. If in doubt, you don't get in.
Scouted entries, coloured by today. The colour is the sea state at the spot, not a guarantee: the wash and a slippery entry you judge on site.
Open the seafloor mapThe full spot briefing is part of the subscription: entry, bottom, hazards, tide window.
Open in the appThe only proper rock formation on the Piauí coast, on Ilha Grande de Santa Isabel: one calm sheltered side and one exposed side with surf. Shore entry, 2–8 m as reported and unmeasured. It sits in the Delta do Parnaíba APA.
Cameras, map and reference — to hand as you come up.
The full spot briefing is part of the subscription: entry, bottom, hazards, tide window.
Open in the appSOLO 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.
Rules change and vary by state. Before heading out, check on gov.br (recreational licence, MPA) and the state closed seasons/sizes; apnea only, goliath grouper is banned.
Parnaíba has rock entry points such as Pedra do Sal, Naufrágio ao largo de Parnaíba and Pedra submersa ao largo da Pedra do Sal. Pedra do Sal is the only real rock formation on the Piauí coast: a rough side, a sheltered side and pools between the rocks holding parrotfish and grouper, per the local fishing guide. Below you'll find each spot (access, shelter and hazards) and today's forecast.
Tides reach 3.5 m here and the delta carries sediment all the time; the best days are the dry season (Aug–Dec) with light wind on a high tide.
Warm, ~27–29 °C — rashguard. Sand bottom with isolated rocky «itans»; the water almost always carries sediment and depths are shallow.
Hard on conditions rather than depth: turbid delta water, current and tides to 3.5 m — take a local along the first time.
Yes — in Parnaíba you need the Licença de Pesca Amadora (gov.br portal; the category follows boat use, per the MPA: «desembarcada» R$ 20/yr when you enter from shore, «embarcada» R$ 60/yr with a boat — Portaria 616/2022 itself sets no categories; 65+/pensioners exempt). Breath-hold only (no scuba tank — art. 4º §3º), licence on you (art. 17); take home at most 15 kg + 1 fish and never filleted or headless (arts. 8º and 12); don't sell the catch (art. 6º). A marker buoy is mandatory in Santa Catarina (IN MMA 21/2005, art. 5º) — there is no federal buoy rule. Goliath grouper (mero) is full no-take, dusky grouper has a 1 Nov–28 Feb closed season, badejo-mira and peroá close on 25/10/2026 (Portaria GM/MMA 1.666/2026, art. 12) and taking lobster while diving is banned all year (Portaria SAP/MAPA 221/2021, art. 6º III). See the guide.