Today — sit it out — 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
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.
Leave your email — and the moment a window opens at Nantucket, 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.
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 mapLedges at the inner entrance to Nantucket Harbour beside the lighthouse, 1–6 m. Very shallow with ferry traffic — dive early and fly a flag; flounder and tautog.
Google MapsEntry from the beach at Francis Street Beach, 0.5 km out of Nantucket. Access type in the Massachusetts CZM data: beach. Expect no more than about 3 m of water. On a line to the north-east, NOAA bathymetry gives roughly 1.9 m at 50 m and 2.8 m at 200 m out.
Google MapsStone jetty running into Nantucket Sound at the harbour's outer entrance, 1–6 m. Rock structure beside a sandy swimming beach — flounder and tautog; keep clear of bathers.
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.
Cameras, map and reference — to hand as you come up.
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».
US spearfishing law is state-by-state. License, spearable species, powerhead rules and distances vary; federal sanctuaries (Gray's Reef, the Keys, Flower Garden Banks) ban spearfishing. Always confirm with the state agency and local ordinances.
Nantucket has rock entry points such as Brant Point Ledges, Jetties Beach Jetty and Francis Street Beach. Nantucket's harbor-mouth ledges and jetty — Brant Point and Jetties Beach hold flounder and tautog. Below you'll find each spot (access, shelter and hazards) and today's forecast.
Jun–Oct; Cape Cod and the islands, tautog and black sea bass.
Cool, 12–18 °C; moderate viz, best off the islands.
Intermediate: cool with headland current, best off the islands.
Yes — in Nantucket almost certainly, but the licence is the STATE's, not a federal one: nearly every coastal state requires its own saltwater fishing licence, and several add a free registration or an extra endorsement on top (Florida's free State Reef Fish Survey for reef fish, Texas's saltwater endorsement, California's Ocean Enhancement Validation). Hawaii asks nothing of residents and charges visitors the NRMFL. What may be speared, and with what gear, is state law too — the price and the details depend on the state, so read the «Law» block below.
