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
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 Mackinaw City, 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.
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 mapSchooner of 1895 lying in 2-8 m with her cargo of cut sandstone blocks still stacked in the hull. The shallowest good site in the Straits, snorkel-friendly on a calm day, but fully exposed to north wind.
Google MapsThe 604 ft freighter sunk in a 1965 collision, lying on her starboard side and broken nearly in two; hull reachable at 12 m, bottom at 32 m. Partly inverted, so disorientation is real. Buoyed bow, stern and midships. A protected grave site.
Google MapsWooden bulk freighter of 1888 cut by ice in 1909, upright and intact with deck at 34 m and bottom near 44 m. Advanced boat dive five miles west of the bridge; cold, dark and swept by Straits current. Engines, boilers and a mushroom anchor are the draw.
Google MapsSmall wooden steamer run down in 1890, sitting in 30 m west of the bridge with engine and stern deck railing intact. A compact, well-preserved boat dive; visibility is usually good but the Straits current is unforgiving.
Google MapsGraceful 141 ft schooner sunk in an 1871 collision, hull largely whole in 21-26 m with windlass and deck fittings in place. Boat dive from Mackinaw City, usually buoyed; visibility is excellent but the Straits current demands a line.
Google MapsSteamer of 1873 lost to ice in 1894, lying just south-west of the bridge's south tower with boiler piping at 28 m and the bottom at 38 m. Game fish gather on the wreck and currents can run very strong - slack water only.
Google MapsSchooner lost in 1898 and lying in 16-22 m in the Lake Michigan approach to the Straits, shallow enough for a long bottom time. Boat dive; plan for current and the ferry lanes. North of Grand Haven, so no game fish may be speared here.
Google MapsBrig of 1848 lost with all hands in 1856, sitting upright in 21-24 m with a figurehead on her prow and deck reachable at 21 m. Buoyed in season, straightforward boat dive west of the bridge; current picks up on the turn. Artefacts are protected.
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».
Mackinac Bridge AuthorityMackinaw City sits where Lake Michigan meets Lake Huron, over the densest shipwreck collection in the state. Michigan's 2026 underwater-spear permission is a list of named waters and this one is not on it, so what is open here is the year-round list — whitefish, cisco, burbot and the rough fish. Scuba is banned for spearfishing statewide, the free underwater licence is mandatory, its monthly reports abolished in 2026, and the Straits current means slack water or nothing.
Depths are the ones published for each site; the level column is the dive, not a promise about the fish. On this coast the shallow structure is where a freediving hunter actually works — Michigan bans scuba for spearfishing, so anything under the thermocline is a dive to look at, not a place to hunt.
| Spot | Type | Depth | Level | Access | Notes |
|---|---|---|---|---|---|
| Sandusky | Wreck | 21-24 m | Advanced, slack water only | Boat west of the bridge, buoyed in season | Brig of 1848 lost with all hands in 1856, sitting upright with a carved figurehead on her prow and the deck reachable at 21 m. Artefacts are protected; the current picks up on the turn. |
| Cedarville | Wreck | 12-32 m | Advanced, boat only | Buoyed at bow, stern and midships | The 604 ft freighter sunk in a 1965 collision, lying on her starboard side and broken nearly in two; hull at 12 m, bottom at 32 m. Partly inverted, so disorientation is real, and this is a grave site. |
SpainUS 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.
| Maitland | Wreck | 21-26 m | Intermediate to advanced, descent line required | Boat dive from Mackinaw City, usually buoyed | Graceful 141 ft schooner sunk in an 1871 collision, hull largely whole with windlass and deck fittings in place. Visibility is excellent, but the Straits current demands a line. |
| C.H. Johnson | Wreck | 2-8 m | Novice, snorkel-friendly on a calm day | Boat; the shallowest good site in the Straits | Schooner of 1895 with her cargo of cut sandstone blocks still stacked in the hull. Bright and easy, but fully exposed to any north wind. |
Yes, but as a rough-fish and whitefish fishery rather than a game-fish one. Michigan is the only Great Lakes state with a purpose-built underwater spearfishing regime, and Mackinaw City is inside it. The 2026 regulations name the waters where lake trout, northern pike and walleye may be taken with an underwater spear, and this water is not among them. Bring the gun, expect whitefish, cisco, burbot, carp and suckers, and leave the lake trout alone even when it swims past the Cedarville.
The Straits are a channel, not a bay. Lake Michigan and Lake Huron exchange through a gap a few miles wide beside the Mackinac Bridge, and the current that makes is the defining feature of every dive: the preserve's own wreck notes say slack water only, and a descent line is normal even on a 21 m site. Ice closes the water January to March; the dive season is June to October, and visibility on these wrecks is described as excellent, improving as the summer plankton drops away. There is no tide to plan around, so the day is built on wind and current instead.
Michigan's Bow & Spear Fishing table — the Fisheries Order under NREPA Part 487 — is an enumerating list: whatever it does not name cannot be taken. Michigan's 2026 underwater-spear permission is a list of named waters and this one is not on it, so the game fish are shut here. Open is the year-round all-waters list — bowfin, bullheads, burbot, common carp, catfish, cisco, freshwater drum, gizzard shad, goldfish, grass carp, longnose gar, rainbow smelt, suckers and lake whitefish. Whitefish, cisco and burbot are real Great Lakes fish, so that is no consolation prize. Lake sturgeon is never a spear target.
Yes, and twice over. First the ordinary Michigan all-species licence: $26 resident annual, $76 nonresident annual, $10 daily, $11 resident senior, required from age 17, licence year 1 March to 31 March. Then the document most visitors miss — anyone spearfishing underwater must be issued a free annual underwater spearfishing licence, and it is still mandatory, though the monthly effort-and-harvest reports it used to carry were abolished for the 2026 season. That licence is a legal condition of the fishery, not a courtesy.
The current comes first: on the Minneapolis, near the bridge's south tower, it can run very strong and the site is workable only at slack. Traffic is second — the bridge corridor and the St. Ignace ferry lanes move boats over your head all day. Third is depth and darkness: Eber Ward bottoms near 44 m, and the Cedarville is partly inverted, which is a disorientation risk rather than just a deep one. Cold is the constant: fresh water that stays cold below the first few metres, with the deeper sites under the thermocline. Tow a diver-down flag — but the rule forbids spearfishing where that flag would block boat navigation or access to a launch, and keeps you 150 feet off swimming areas, docks, boat access sites and power intakes, from 30 minutes after sunset to 30 minutes before sunrise. The gear is freediving gear, thicker than a sea diver expects: scuba and rebreathers are banned, so the whole day is breath-hold in fresh water that warms only at the surface, and a 7 mm suit or a hooded two-piece is the baseline for a June–October season, with gloves and boots for pier rubble and wreck steel. Legal gear is a hand-, rubber- or spring-propelled spear; a rubber or spring spear may be fired only fully submerged and must be tied to a line no longer than twenty feet, with the bands off and the safety on whenever you move between areas or enter and leave the water.
Yes, but only for Michigan's year-round list — whitefish, cisco, burbot, carp, catfish, suckers, drum, gar, smelt, bowfin, bullheads, gizzard shad, goldfish and grass carp. The 2026 regulations do not name this water, so no lake trout, pike or walleye.
June to October. Ice closes the water January to March, and visibility is best late in the season once the summer plankton has dropped out.
No. The Straits of Mackinac Shipwreck Preserve is a Michigan bottomland preserve under NREPA Part 761. It is not a fishing closure, but nothing may be lifted, and the Cedarville is a grave site.
Michigan's 2026 underwater-spear waters are named lake by lake: Lake Michigan from the MI/IN border to the 45th parallel, a 2-mile strip in Green Bay to the Ford River mouth, a 5-mile strip from Point Detour to the Brevort River, Lake Huron from the Thunder Bay River pier at Alpena south to Fort Gratiot Light, Lake Erie to the Celeron Island line, and Lake Superior to the St. Marys River — with Grand Traverse Bay, Stannard Rock, Big Reef and the 4.5-mile ring round Isle Royale cut out of them. Michigan's 2026 underwater-spear permission is a list of named waters and this one is not on it, so what is open here is the year-round list — whitefish, cisco, burbot and the rough fish.
No. Artificial breathing devices such as scuba and rebreathers are prohibited while underwater spearfishing, and the diver must be fully submerged to fire a rubber- or spring-propelled spear. Michigan's underwater fishery is freedive only.
Portugal
