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Entry between rocks onto a shallow reef of table and branching coral, maximum about 6 m. Marine park zone — take nothing.
Google MapsToday — 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 Kashiwajima, 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 mapEntry between rocks onto a shallow reef of table and branching coral, maximum about 6 m. Marine park zone — take nothing.
Google MapsEntry from the jetty at Amaji straight onto shallow, dense coral with sand patches. Calm, easy shore site; keep clear of boats using the harbour. Hand spear only — no speargun, no scuba.
Cameras, map and reference — to hand as you come up.
Japan: spearguns and scuba/hookah are banned for all recreational fishers nationwide (Fisheries Agency prefectural gear table); a hand spear (yasu) is allowed only in some prefectures (e.g. Okinawa, Kagoshima, Nagasaki, Kochi, Mie); abalone, lobster, octopus and sea urchin in fishery-right areas belong to the local co-op, and marine park zones are closed. Check current rules locally.
Sandy inlet (Tatsu-no-hama) on Kashiwajima at 5–12 m with rubble and small table corals at the edges. Local dive services run it by boat, a 4–5 minute ride. Hand spear only — no speargun, no scuba.
Google MapsReef, rock reef, 3–25 m, by boat. Hand spear only — no speargun, no scuba. Coords approx.
Google MapsCoral-covered reefs off Okinoshima (Akasaki) reached by boat, average around 10 m and down to 25 m, with sand below the coral. Current is rare. Hand spear only — no speargun, no scuba.
Google MapsSandy bay with scattered rocks to about 6 m, mostly used for snorkelling and try-dives. Marine park zone — take nothing.
Google MapsShallow reefs around Benten-jima at Tatsukushi, about 5–13 m, with large encrusting and branching coral patches. Beach entries are a short distance north at Tsumashiro. Marine park zone — take nothing.
Google MapsBeach entry used for training, with encrusting coral patches and a maximum of about 7–10 m. Shallow and easy, but open water fish do pass in summer. Marine park zone — take nothing.
Google MapsKashiwajima's best-known site: table-coral gardens 5–12 m along 500–600 m of the north shore, with sand and rubble, sloping to about 30 m. Dived from moored buoys by boat. Hand spear only — no speargun, no scuba.
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.
Kashiwajima has rock entry points such as Kashiwajima east, Kashiwajima west and Okinoshima. A tiny island off Otsuki at Shikoku's SW tip where the Kuroshio sweeps in — over a thousand fish species, coral and rock reefs and very clear water in autumn. Below you'll find each spot (access, shelter and hazards) and today's forecast.
June–November; the Kuroshio keeps the water warm into late autumn, winter brings the north-west monsoon, and typhoons come August–October.
14–17 °C in February–March, 26–28 °C in August — 5–7 mm in winter, 3 mm in summer.
Rocky capes and reefs, Pacific swell and currents off the points. Spearguns and scuba are banned nationwide — only a hand spear (yasu), where the prefecture allows it; shellfish, lobster, octopus and urchin in fishery-right areas belong to the co-op.
Kashiwajima: Japan: spearguns and scuba/hookah are banned for all recreational fishers nationwide (Fisheries Agency prefectural gear table); a hand spear (yasu) is allowed only in some prefectures (e.g. Okinawa, Kagoshima, Nagasaki, Kochi, Mie); abalone, lobster, octopus and sea urchin in fishery-right areas belong to the local co-op, and marine park zones are closed. Check current rules locally.