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 Chicago, we'll send the go / no-go verdict. Email is all we need.
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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: 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 mapThe outer breakwall guarding Chicago Harbor, armour stone dropping into 3-8 m and the city's main hard structure. Boat access only, heavy traffic and no shore entry - Illinois also bars taking aquatic life from any public right-of-way.
Google MapsSelf-unloading barge that capsized in a 1936 squall off Calumet Harbor with the loss of fifteen crew, now a boat dive on sand in roughly 12 m. Cold and often murky; go after a spell of west wind. Not a spearfishing site under Illinois law.
Google MapsCameras, 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».
Spaintransparency ~6 m · satellite, yesterdaysatellite estimate · may differ right at the shore
Excursion steamer stranded on Morgan Shoal in 1914; her boiler still breaks the surface off 49th Street and plating lies over the shoal rock in a few metres. Chicago's only true shore dive, best on a flat morning. Illinois authorises no game fish by spear.
Google MapsCharted wreck off the Calumet shore in southern Lake Michigan, a boat dive from Calumet Harbor over sand and scattered structure. Visibility swings with the river plume and any east wind. Illinois lists no game fish as spearable - a dive site only.
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.
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.
Illinois is the state that names your gun and then gives it nowhere to go. 17 Ill. Adm. Code 810(a) lists the underwater spear gun as a lawful method, but 810(b) limits it to native rough fish and non-native species — no trout, no salmon, no perch, no walleye, no pike, no bass, no whitefish — and 810(d), which enumerates the waters open to these methods, does not name Lake Michigan. Whether the site-specific rule 810.45 reaches the lake is unresolved. So the honest answer for Chicago is: restricted and unresolved, confirm with IDNR, and treat the wrecks as dive sites.
Chicago's diving is a handful of wrecks and one big piece of harbour structure. Every row here is a dive site under the reading above, not a hunting mark. Note the access column carefully: Illinois also makes it unlawful to take or attempt to take aquatic life along, upon, across or from any public right-of-way, which bites hardest on a lakefront where most access is public shoreline structure.
| Spot | Type | Depth | Level | Access | Notes |
|---|---|---|---|---|---|
| Silver Spray | Wreck | 2-5 m | Shore dive · dive site only under Illinois law | Shore, off 49th Street | Excursion steamer stranded on Morgan Shoal in 1914; her boiler still breaks the surface off 49th Street and plating lies over the shoal rock in a few metres. Chicago's only true shore dive, best on a flat morning. |
| Chicago Harbor Exterior Breakwater | Jetty | 3-8 m | Boat dive · dive site only under Illinois law | Boat | The outer breakwall guarding Chicago Harbor, armour stone dropping into 3-8 m and the city's main hard structure. Boat access only, heavy traffic and no shore entry. |
| M/V Material Service | Wreck | 12 m | Boat dive · dive site only under Illinois law | Boat | Self-unloading barge that capsized in a 1936 squall off Calumet Harbor with the loss of fifteen crew, now a boat dive on sand in roughly 12 m. Cold and often murky; go after a spell of west wind. |
| Tacoma | Wreck | 5-12 m | Boat dive · dive site only under Illinois law | Boat | Charted wreck off the Calumet shore in southern Lake Michigan, a boat dive from Calumet Harbor over sand and scattered structure. Visibility swings with the river plume and any east wind. |
Restricted, and on Lake Michigan unresolved. 17 Ill. Adm. Code 810(a) is explicit that aquatic life listed in subsection (b) may be taken by means of a pitchfork, underwater spear gun, bow and arrow or bow and arrow device, spear or gig, with a valid sport fishing licence, and that no other aquatic life may be taken in this State by these means. Subsection (d), "Waters Open to Bowfishing and Other Legal Archery and Spearfishing Methods", then enumerates site-specific waters under Section 810.45 plus the Mississippi, Illinois, Sangamon, Kaskaskia, Big Muddy, Saline and Ohio Rivers, plus the Embarras, Skillet Fork and Cache. Lake Michigan is nowhere in that list. Whether 810.45 reaches it could not be resolved in this research, so we publish the restricted-and-unresolved answer rather than a green light.
Subsection (b) is two groups. Native rough fish: gars, buffalo, bullheads, redhorse, catfish, blue sucker, bowfin, drum, gizzard shad, carpsuckers and suckers. Non-native fish: bighead, black, common, grass and silver carp, goldfish, northern snakehead, oriental weatherfish, pacu, round goby, sea lamprey, tilapia and white catfish. Naming round goby and sea lamprey makes Illinois the clearest "invasives are legal targets" text of the eastern states — and, on Lake Michigan, also the emptiest, because those are effectively the only species on the list that live there. Two further details: no live possession of non-native fish is permitted except common carp and goldfish, and there is a documented conflict — the site-specific regulation code definition allows carp, carpsuckers, buffalo, gar, bowfin and suckers by pitchfork, gig, bow and arrow, with no spear gun and a narrower species set, so a water opened by that code may be open to a bow and closed to a gun.
Illinois makes it unlawful for any person to take or attempt to take aquatic life along, upon, across or from any public right-of-way or highway in this State. On the Chicago lakefront that is not a technicality: most of the accessible shoreline is public structure — revetment, breakwater, seawall, pier — and the outer breakwall is boat-access only in any case. Combine that with 810(d)'s silence on Lake Michigan and the practical picture is clear: plan Chicago as a dive trip, and if you want to spearfish, the natural move for an Illinois diver is north across the Wisconsin line, where the panfish and rough-fish carve-out of the Outlying Waters rule is written down and settled.
Chicago is the only Great Lakes metropolis with a living dive scene: the Underwater Archeological Society of Chicago searches for, documents and dives the city's wrecks. The Silver Spray is the one true shore dive — an excursion steamer stranded on Morgan Shoal in 1914, her boiler still breaking the surface off 49th Street, with plating over the shoal rock in 2-5 m, best on a flat morning. Off Calumet Harbor the M/V Material Service, a self-unloading barge that capsized in a 1936 squall with the loss of fifteen crew, lies on sand in roughly 12 m; the charted Tacoma sits in 5-12 m nearby. The Chicago Harbor exterior breakwater gives 3-8 m of armour stone but is boat-access only with heavy traffic overhead.
Harbours and canals ice from January to March while mid-lake stays open. The season runs June to October and the best visibility is August to October. The two Calumet sites are the ones to time: visibility there swings with the river plume and any east wind, and the Material Service entry recommends going after a spell of west wind. Below the surface layer the water stays cold, so plan a drysuit or heavy semi-dry even in August. There is no tide — the Great Lakes astronomical range is a few centimetres and NOAA publishes no predictions for these stations. An Illinois sport fishing licence costs $15.00 resident annual, $31.50 non-resident annual, $15.50 non-resident 3-day and $10.50 for 24 hours; the $6.50 Lake Michigan Salmon Stamp is irrelevant here, since neither trout nor salmon is spearable. Illinois night and scuba rules for spearing were not found in this research — that means the search failed, not that no rule exists.
Restricted and unresolved. Illinois names the underwater spear gun as legal gear in 17 Ill. Adm. Code 810(a), but only for the 810(b) allow-list, and 810(d) does not name Lake Michigan. Confirm with IDNR.
Yes, as a method: 810(a) names the underwater spear gun. The limit is the species list and the list of open waters, not the gear.
No. The 810(b) list holds no game fish — no trout, no salmon, no yellow perch, no walleye, no pike, no bass, no whitefish.
On the Illinois list, yes: round goby, sea lamprey, snakehead, the four carps, goldfish, tilapia, pacu, oriental weatherfish and white catfish are all named.
Illinois bars taking aquatic life along, upon, across or from any public right-of-way, and most lakefront access is public structure. Treat the lakefront as closed to it.
The Silver Spray on Morgan Shoal off 49th Street, in 2-5 m, with her boiler still breaking the surface. Best on a flat morning.
Resident annual $15.00, non-resident annual $31.50, non-resident 3-day $15.50, 24-hour $10.50. The $6.50 Lake Michigan Salmon Stamp does not help a spearo.
North across the Wisconsin line, where the Outlying Waters rule gives a written panfish and rough-fish carve-out with skin and scuba diving expressly allowed.
Portugal
