Scuba Diving · Florida Keys

Scuba Diving in Key West

Southernmost reef structure in the continental US. Marquesas and Dry Tortugas trips for permit, tarpon, and offshore pelagics. Shallower patch reefs inshore for snapper and grouper.

Live conditions, water-clarity forecast, and water temperature for scuba diving in Key West, 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

26 ft

16–42 ft range

Water

86°F

Wind

8 kts

Wave

1.9 ft

Swell

1.8 ft

Period

3.5s

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

Notable species

Key West is known for:

PermitTarponYellowfin TunaWahooMutton Snapper

Typical water visibility

Summer visibility around Key West 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 West. 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	16	26	41
Oct 4	14	21	34
Oct 3	14	21	34
Oct 2	14	21	32
Oct 1	14	21	32
Sep 30	17	24	37
Sep 29	14	28	41

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

Clearest months at Key West

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	20	21	low
Feb	45	45	low
Mar	40	45	low
Apr	26	26	low
May	26	48	low
Jun	25	48	low
Jul	26	45	low
Aug	26	43	low
Sep	26	43	low
Oct	26	43	low
Nov	25	41	low
Dec	25	37	low

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

What Submarius shows for Key West

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 West specifically, the app shows any recent tagged sharks within range and lets you enable push notifications for sightings on your active tiles.