Today — right on the edge — wave, wind and surge pounding.
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 Matemwe (Zanzibar), we'll send the go / no-go verdict. Email is all we need.
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: 3016 spots across 406 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 mapReef wall, boat access, depth not given by the source. No hunting — Mnemba Island Marine Conservation Area (MIMCA) (approx. boundary). Reef mapped in OpenStreetMap and named by local dive operators.
Google MapsReef, boat access, depth not given by the source. No hunting — Mnemba Island Marine Conservation Area (MIMCA) (approx. boundary). Position from a dive-site directory, approximate.
Google MapsCameras, map and reference — to hand as you come up.
Tanzania: operators report that speargun fishing is banned on the mainland (Fisheries Act 2003 / Regulations 2009) and that Zanzibar issues sport-spearfishing licences only through registered operators. The acts could not be read — treat this as unconfirmed and check with the Fisheries Division. Marine parks and reserves are closed to hunting. Night rules not verified.
Reef wall, boat access, depth not given by the source. No hunting — Mnemba Island Marine Conservation Area (MIMCA) (approx. boundary). Reef mapped in OpenStreetMap; no diver reports — unverified.
Reef, boat access, 2–5 m (source). The busiest site in Zanzibar — watch for boats. No hunting — Mnemba Island Marine Conservation Area (MIMCA) (approx. boundary). Pin from a snorkelling guide's map.
Google MapsReef, boat access, 5–12 m (source). No hunting — Mnemba Island Marine Conservation Area (MIMCA) (approx. boundary). Position from a dive-site directory, approximate.
Google MapsSOLO 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.
Matemwe (Zanzibar) has rock entry points such as Mnemba Island reef (snorkel area), Big Wall (Mnemba) and Little Wall (Mnemba). Matemwe on the north-east coast is the closest base for Mnemba: boats leave from Muyuni and take about 20 minutes. Below you'll find each spot (access, shelter and hazards) and today's forecast.
The NE monsoon (Kaskazi, about Nov–Mar) is the calm season; the SE monsoon (Kusi, about Jun–Oct) roughs up the east coast, while the west side stays sheltered.
About 28–30 °C in January–March and 24–26 °C in July–September (forecast SST supersedes).
Macro-tides: east-coast lagoons drain hundreds of metres at low tide, so shore entries are tide-locked; boat and jet-ski traffic at Nungwi, Pingwe and Mnemba.
Matemwe (Zanzibar): Tanzania: operators report that speargun fishing is banned on the mainland (Fisheries Act 2003 / Regulations 2009) and that Zanzibar issues sport-spearfishing licences only through registered operators. The acts could not be read — treat this as unconfirmed and check with the Fisheries Division. Marine parks and reserves are closed to hunting. Night rules not verified.
