Isla Mujeres · Mexico

8.2

wave 0.6 m head-on

visibility5m

Dive today — wave, wind and visibility.

Sources: IPMA · NDBC · Copernicus — high confidence · data 13:31

Sources & confidence

Sources: IPMA · NDBC buoys · Copernicus Marine
Method: Model consensus, read per window
Freshness: Re-read every hour, per coast

Compiled by the spearo sea-state engine

The verdict comes from seven water factors and hard safety gates — not ten tabs. Go or stay.

How we score the water

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.

Swell & wave memory: Height, period and direction of the swell, plus the wake of recent storms — an old storm still stirs the water, and the engine remembers.
Wind & gusts: Speed and gusts, hour by hour — wind speed and an onshore push chop the surface and cut visibility.
Tide phase: Timing and range of the tide, calibrated per coast — big spring tides pull the verdict toward caution.
Water temperature: Sea-surface temperature — sharply cold water vetoes a green verdict.
Currents & outflow: Direction and drift of the current — it pushes you, and it drags turbid coastal water across where you dive.
Rain runoff & air clarity: Rain muddies the water inshore through land runoff, while fog and haze cut visibility at the surface.
Coast shape & exposure: How the coast faces the swell — a sheltered cove keeps the water clean; an exposed, head-on point takes a penalty.

Safety gates

Thunderstorm forecast — an instant red, no exceptions.
An official warning (MeteoAlarm / IPMA) — yellow, or red for the higher ranks.
Missing input data — a would-be green is capped to yellow rather than overstated.
Strong disagreement between forecast models — a green day is pulled back to yellow.
Night hours — forced red; the window is closed after dark.

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

Entry points with coordinates

Seabed relief — promising ground

This verdict — in your pocket. Open the app for the week's window.

Android: the public release is in Google Play review — leave your email and we'll send beta access today.

Android beta — QR code — point your camera

0 m

Surface

Wind, wave and the swell windows — when to go and the best hours.

spearo.app

calmupdated 13:31

Isla Mujeres — solo, off the rocks

BEST WINDOW

best weather window · solo, stay careful, run the checklist · calm conditions: swell, wind and visibility all normal

wave 0.6 m head-onwind 11, gusts 31 km/hvisibility ~7 mwindow 12:00–21:00

today, best window 18:00–21:00

fish · Visibility 7 m · Water 29.1°C

confidence high · verdict for the selected day

Before entering, check the camera and the surge

Whole week — tap a day. is driving swell right now.

Solo risk: carry a float · tell someone your plan and exit time · doubt = don't go. A model-based planner; the call is made on site.

Selected day

Windows, hours
and the day's trends.

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.

Wednesday · today2026-07-22

06:17–19:30 · first quarter

▲ 05:00▼ 12:00▲ 18:00▼ 23:00 · 0.2 m

Hours (06→20)

Day's trends

Tide-0.23 m

Wave0.58 m

Wind7 km/h

Water29 °C

fish activity: moonset 00:33 · moderate · moon underfoot 07:20 · high · moonrise 14:03 · moderate · moon overhead 19:40 · high

Conditions window12:00–15:00

caution — solo off the rocks is risky, check on site fish

Hs 0.56 mperiod 4.7 s head-onwind 14→35surge 0.7viz 5 m

0.56 mup to ~1.12 · 116° head-on

4.7 sswell moderate

14→35gusts 35 km/h

0.7weak surge

0.11m/s

5 mrecent swell

29.1°C5 mm + hood

▲18:00tide turn near

Atmosphere43 kmlandmarks visible

moderatemoonrise

strong wind 14 km/h, gusts 35 — caution
visibility ~5 m

confidence highday

Open the seafloor map with entry points

Your best window — with you. Forecast in your pocket.

Android: the public release is in Google Play review — leave your email and we'll send beta access today.

−10 m

The water column

Visibility and what drives it — post-storm clearing, river plume, temperature and the thermocline.

What it is

A marine instrument,
go / no-go for solo hunting.

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: 1152 spots across 189 stretches of coast — mainland Portugal, Madeira and the Azores.

See all spots

−20 m

The seabed

Relief and bottom type, tides, and the depths of each spot.

On the rock

The forecast is the plan.
The call is on the rock.

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.

Entry points

Where to get in
off the rocks.

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 map

Bancos exteriores (fuera del PN)Isla Mujeres

borderline

exposed head-on to the swell today

window
tide
shelter
hazard
access

Banks outside the NP polygons, 5–15 m, by boat; lionfish only on the reef. Coords approximate, check your water entry.

Google Maps

SOLO 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.

One morning glance — and you know.

Android: the public release is in Google Play review — leave your email and we'll send beta access today.

≈

Surfacing

Cameras, map and reference — to hand as you come up.

Live cameras, map & reference

Cameras · live

Look at the water
right now.

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».

connecting to the stream…

● LIVE↗

Isla Mujeres — Playa NorteLive — Isla Mujeres — Playa Norte. webcamsdemexico network camera (YouTube-live); the videoId rotates, so the stream is re-scraped on the fly by our proxy. Read the water before you go.camera: webcamsdemexico ↗

Open the seafloor map →

Reference

What's in season,
what the law says.

In season now

mutton / dog snapper
5–20 m · on the current by structure · dusk/night
Reef snapper on the edge & drop-offs; work the reef rim on the current, best at dusk/night. Warm months. Mexican rule sets no minimum size.
red grouper
8–30 m · on the current by structure · daytime
Grouper on reef ledges & holes — stalk slowly along the bottom. ⚠️ Yucatán closed 1 Feb–31 Mar; off-season take sparingly (vulnerable). Mexican rule sets no minimum size.
crevalle jack
1–20 m · on the current by structure · daytime
Fast crevalle jack on the reef edge, by day — shoot on the current, quick. No minimum size in the rule.
great barracuda
1–25 m · on the current by structure · daytime
⚠️ Big barracuda/reef predators in the Caribbean — ciguatera risk. Eat small ones, avoid big reef fish.
lionfish
3–40 m · on the current by structure · daytime
Invasive — culling ENCOURAGED year-round. Tucks under ledges / in reef shade and lets you get close. Venomous spines — handle with care; excellent eating.

off season: hogfish (Dec Jan Feb Mar Apr May Jun)

Not a target — don't shoot

Nassau grouper🚫 no-take
🚫 Nassau grouper — protected (critically endangered): do not take, release. Slow-growing, forms spawning aggregations.

Law

✓A /SADER recreational-sport fishing permit is required (online via E5CINCO; day/week/month/year). Apnea only — spearing on scuba is banned.
✓One speargun (band or pneumatic), no hooks/tridents; 5 fish/day; barred within 250 m of swimmers or commercial gear.
✓Reserved to rod-and-reel sport fishing (do NOT spear, conservative rule): marlin, sailfish, swordfish, tarpon, roosterfish and dorado. Lobster, conch and octopus are outside sport fishing.
✓Grouper (mero) closed season to 31 Mar (Gulf/Yucatán focus). Marine ANPs (APFF Islas del Golfo — Espíritu Santo, Balandra) are no-take cores: do not shoot.

⛔ 🚫 Sport spearfishing is fish-only: lobster, conch (caracol) and octopus may NOT be speared (squid is the sole exception). §4.2.
⛔ 🚫 Totoaba, sea turtles, marine mammals and corals — no-take (). Inside the national parks (Cabo Pulmo, Cozumel, Puerto Morelos, Revillagigedo) all hunting is banned.

Rules change. Before heading out, check with CONAPESCA/SADER (E5CINCO permit), CONANP (no-take marine ANPs) and NOM-059; apnea only.

Safety protocol

Sets: watch the wave trains ≥15 min before entering; Hmax ≈ 2×Hs, the wash can run 50 m past the foam line. A lull >10 min with period >12 s = a big set «overdue», do NOT enter; enter right after a full set passes and re-check at minute 30.
Exit FIRST: find your exit AND a backup before entering. On a rocky/boulder shore a 0.5 m rise in swell can make the exit impossible — getting pinned/unable to climb out is the main killer.
Headland rip: prominent points often have a permanent topographic rip regardless of the model — locate it, enter/exit on the windward side, never swim against it.
Cold: wetsuit per the SST chip; the first shiver = a metabolic surge and a drop in breath-hold → get out at the first steady shiver. Cap the session at 45–60 min below 15 °C.
Solo discipline: buoy up; tell someone the spot and exit time; conservative breath-hold (never push it in cold/murky/surfy water); visibility <3 m — don't enter.
Afternoon wind: on many coasts the wind builds from midday — plan to be out of the water by midday; the chop builds — get out.
UV 11:00–15:00 (UVI ≥6): sunscreen and cover up on the surface interval.
Solo is a fundamental risk (hypoxic blackout with no buddy). Any doubt = No-go.

FAQ — spearfishing in Isla Mujeres

Where can I spearfish in Isla Mujeres?

Isla Mujeres has rock entry points such as Bancos exteriores (fuera del PN). Isla Mujeres has reefs and the MUSA underwater museum, but the West Coast NP cuts the best zones: the reef is no-take and only lionfish is a legal target. Below you'll find each spot (access, shelter and hazards) and today's forecast.

When is the best season in Isla Mujeres?

Warm, clear reef water; best winter–spring (low sargassum). Sargassum Apr–Oct clouds the shore, hurricanes Jun–Nov. Many no-take parks — hunt outside them.

How cold is the water in Isla Mujeres?

Warm, ~26–29 °C — rashguard or 2 mm. Clear reef water (10–40 m); sargassum Apr–Oct cuts visibility in places.

Is Isla Mujeres good for a beginner?

Beginner-friendly: warm, clear reefs on calm days — ideal, but many no-take zones (hunt only outside the parks).

Do I need a licence in Isla Mujeres?

In Isla Mujeres spearfishing is legal but breath-hold only (freediving — NOM-017-PESC-1994 §4.5; no scuba/hookah), and an individual CONAPESCA permit is ALWAYS required, including from shore (the "from-the-beach, no permit" idea is a myth). Fish only (no lobster, conch or octopus — squid is the one exception), max 5 fish/day, and keep 250 m off swimmers and boats. Dorado, marlin, sailfish and roosterfish are reserved for rod-and-reel in the 50-mile belt — better not to spear them. Yucatán grouper closed season 1 Feb–31 Mar; totoaba is permanent no-take. See the guide.

Full guide: hurricanes and Nortes: seasonal spearfishing safety in Mexico →

Coming soon