Today — right on the edge — wave, wind and visibility.
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 Numazu (Osezaki), 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 mapBeach in front of the Hirasawa dive facility with several entry points; kelp forest, sand and coral patches from about 5 m to 23–25 m, little current. Guide lines on the bottom. Spearing not permitted in Shizuoka — check local rules.
Google MapsCobble beach about 200 m wide with no sand at the waterline; steep Suruga Bay slope from shallows to about 35 m (average 15 m). Very clear water; current sometimes enters. Spearing not permitted in Shizuoka — check local rules.
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.
Outer-side beach point: over boulders to sand with soft corals, average about 20 m, maximum 30 m; small caves and crevices in the shallows. Spearing not permitted in Shizuoka — check local rules.
Google MapsEntry anywhere along a 200 m pebble beach inside the cape; boulders in the shallows give way to sand at 7–10 m, maximum about 20 m. Sheltered from most winds and rarely closed; a diving fee is charged by the local cooperative. Spearing not permitted in Shizuoka — check local rules.
Google MapsOuter-side point Sakushita: easy concrete-slope entry, average about 18 m with a drop-off near 30 m. Exposed to open-sea swell more than the inner bay. Spearing not permitted in Shizuoka — check local rules.
Google MapsBeach entry over boulders at the tip of the cape; soft corals and gorgonians, then the bottom drops suddenly, average about 20 m, maximum 30 m. Current can be fast — intermediate divers. Spearing not permitted in Shizuoka — check local rules.
Google MapsConcrete-ramp beach entry onto a wide sand shelf at about 5 m, then a steep slope to 40 m along guide lines. Usually little current; deep water close in — watch depth. Spearing not permitted in Shizuoka — check local rules.
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.
Numazu (Osezaki) has rock entry points such as Osezaki inner bay (Wannai), Osezaki tip (Sentan) and Osezaki outer bay. Suruga Bay's inner coast with Osezaki, the sand spit pointing at Mount Fuji — Japan's busiest training dive site, deep water close in and odd deep-sea fish in winter. 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.
Numazu (Osezaki): 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.
