Scuba Diving · Florida Keys

Scuba Diving in Key Largo

Diving capital of the US. Crystal-clear tropical water, shallow patch reefs, and deep wrecks including the Spiegel Grove and Duane. Consistently 30–80ft vis in summer, more volatile in winter.

Live conditions, water-clarity forecast, and water temperature for scuba diving in Key Largo, FL. Open the app for a live verdict and a tappable factor breakdown, free, no signup. Pro extends the forecast to 8 days.

Open live conditions →

Conditions snapshot: Oct 5, 2026

Visibility

40 ft

22–60 ft range

Water

85°F

Wind

8 kts

Wave

1.0 ft

Swell

1.4 ft

Period

3.4s

Snapshot from Oct 5, 2026. Live values, factor breakdowns, and 8-day forecast in the app.

Notable species

Key Largo is known for:

Mutton SnapperHogfishMahiGrouperYellowtail Snapper

Typical water visibility

Summer visibility around Key Largo is commonly reported in the 30–80 ft range, a community-guidance estimate, not a measurement. Rain, river discharge, swell mixing, and seasonality can shift real conditions dramatically day to day.

That's exactly why Submarius exists. The in-app clarity forecast starts from this coast's typical clarity for the time of year, built from in water measurements and satellite ocean color, then subtracts wave stirring, river and runoff plumes, and tide movement to estimate how far you'll actually see, shown as a low to high range, not a seasonal average.

How the clarity forecast works →

Last 7 days of model reads

One model estimate recorded each morning (UTC) for Key Largo. These are model estimates, not measurements; the low and high columns are the p10 to p90 range around the middle estimate.

Day	Low ft	Estimate ft	High ft
Oct 5	20	40	55
Oct 4	19	32	48
Oct 3	20	34	49
Oct 2	22	31	46
Oct 1	21	30	46
Sep 30	28	41	41
Sep 29	17	47	61

Table baked Oct 5, 2026; days the recorder missed are simply absent.

Clearest months at Key Largo

Model climatology from the baked clarity ceiling: the typical day and the best case (90th percentile) visibility for each month, with a seasonal algae bloom proneness flag. These are labelled model estimates, not measurements.

Month	Typical ft	Best case ft	Bloom risk
Jan	28	36	low
Feb	25	60	low
Mar	38	47	low
Apr	26	45	low
May	40	56	low
Jun	40	60	low
Jul	43	60	low
Aug	43	60	low
Sep	43	60	low
Oct	40	60	low
Nov	28	49	low
Dec	31	49	low

Ceiling artifact global-reef-v10-obis-world; table baked Oct 5, 2026.

What Submarius shows for Key Largo

Verdict score (0–10). Aggregates wind, swell, tide, moon, and water clarity into one decisive number.
Best window. The 2–3 hour stretch each day when conditions peak.
8-day forecast. Auto-scaled line graph showing which day this week is trending good.
Water clarity forecast. Secchi-depth estimate with uncertainty bounds and the next best vis window.
Free, anonymous. Check conditions with location on, no signup until you want to save spots or post reports.

Safety in the water

Submarius ships OCEARCH tagged-shark alerts, community shark sightings, SOS, and buddy GPS sharing, permanently free, regardless of subscription tier. For Key Largo specifically, the app shows any recent tagged sharks within range and lets you enable push notifications for sightings on your active tiles.