IntermediateBoat entry

Blackthorn

Florida, United States

AOW suggestedOffshore Gulf artificial-reef site24 m (80 ft) depthBoat entry3mm wetsuit typical

Blackthorn at a glance

Blackthorn is an intermediate boat dive site in Florida, United States with depths of up to 24.4 m (80 ft). Typically most favorable Jul · from 3 years of archive data. Divers commonly see Gray triggerfish, Red snapper, and Gag grouper. Recent reports put the water around 26°C (79°F). Check the latest conditions and entry details before you go.

Moderate window now· until 17:00 · sunset 16:53

Forecast for this hour · 10:00 · run 23 h ago

1.1 m (3.7 ft)waves — about a meter expected (waves — about four feet expected)

Tap a factor for its source and model point · Forecast 26°C · seasonal avg 26°C ( · Forecast 79°F · seasonal avg 80°F)

Site hazards: Offshore Gulf artificial-reef site

Read the full hazards ↓

Dive windows this week

Lightest wind: Sat

Mon

1.1 m waves · 23 kn wind (3.6 ft waves · 23 kn wind)

Tue

0.9 m waves · 20 kn wind (3.0 ft waves · 20 kn wind)

Wed

1.0 m waves · 17 kn wind (3.2 ft waves · 17 kn wind)

Thu

0.8 m waves · 14 kn wind (2.7 ft waves · 14 kn wind)

Fri

0.6 m waves · 18 kn wind (1.9 ft waves · 18 kn wind)

Sat

0.3 m waves · 11 kn wind (1.1 ft waves · 11 kn wind)

Sun

Favorable windowModerate window— no window

Every forecast dive window each day, site-local time, from wave and wind forecasts. Numbers under each bar are daylight averages.

First light 5:16 · Sunrise 5:39 · Sunset 16:53 · some windows run past sunset

Source: Open-Meteo marine · model point 2.1 km from site · updated 25 Oct, 11:19 GMT-6

Forecast only — always assess conditions on site.

Compare this weekend’s windows near Blackthorn

Forecast · NOAA tide model

Tide & slack timing

Recent diver reports

Dated firsthand observations from divers — not current conditions.

No diver reports for this site yet. — one dated observation helps every diver after you.

Dived here today — did the forecast match?

What Divers Say

Known for: Gray triggerfish, Red snapper, Gag grouper

Best time: May through October offers the calmest seas and clearest water in the northern Gulf; spring water is often murky. Visibility typically 20-60 ft, best in summer.

Based on community reviews and site data. Conditions vary — always verify before diving.

Best months, historically

What conditions have historically been typical at this site, month by month — not a forecast.

January, 66% of days have historically been favorable, water has typically been 17°C (62°F), waves have typically been 1.0 m (3.4 ft), wind has typically been 17 knots
February, 76% of days have historically been favorable, water has typically been 18°C (65°F), waves have typically been 0.8 m (2.7 ft), wind has typically been 15 knots
March, 70% of days have historically been favorable, water has typically been 21°C (70°F), waves have typically been 0.9 m (3.1 ft), wind has typically been 16 knots
April, 77% of days have historically been favorable, water has typically been 24°C (75°F), waves have typically been 0.8 m (2.8 ft), wind has typically been 16 knots
May, 96% of days have historically been favorable, water has typically been 27°C (81°F), waves have typically been 0.6 m (2.0 ft), wind has typically been 14 knots
June, 89% of days have historically been favorable, water has typically been 29°C (85°F), waves have typically been 0.7 m (2.2 ft), wind has typically been 14 knots
July, 99% of days have historically been favorable, water has typically been 31°C (88°F), waves have typically been 0.5 m (1.5 ft), wind has typically been 12 knots, historically most favorable
August, 91% of days have historically been favorable, water has typically been 31°C (89°F), waves have typically been 0.7 m (2.3 ft), wind has typically been 14 knots
September, 94% of days have historically been favorable, water has typically been 30°C (86°F), waves have typically been 0.7 m (2.2 ft), wind has typically been 15 knots
October, 78% of days have historically been favorable, water has typically been 26°C (80°F), waves have typically been 0.9 m (3.0 ft), wind has typically been 17 knots
November, 82% of days have historically been favorable, water has typically been 23°C (74°F), waves have typically been 0.8 m (2.6 ft), wind has typically been 15 knots
December, 82% of days have historically been favorable, water has typically been 19°C (67°F), waves have typically been 0.9 m (2.9 ft), wind has typically been 16 knots

July has typically had the largest share of favorable days here. Conditions vary year to year — this is historical context, not a forecast.

Based on 3 years of archive data. Bar height shows the share of days each month whose conditions have historically scored favorably.

Marine life seen at this site

Species noted at this site — not a promise of what you’ll encounter.

Species seen here

Rough labels: “Commonly seen” usually means two or more recorded sightings near this site in public dive logs (GBIF), “Occasionally seen” one; “Seasonal” and “Rarely seen” come from dive-guide research. Not a measured rate.

Fills & rentals nearby

No dive shops mapped within 25 km (16 mi). Know one? Add it to the map.

Data updated June 2026

Site details

Artificial reef built from 180' Coast Guard Cutter, the "Blackthorn"

reef

Offshore Gulf artificial-reef site — heavy boat and fishing traffic (carry SMB and signaling devices); monofilament line on structure is a common entanglement risk (cutting tool advised); currents magnified around large structures; razor-sharp barnacles and stinging hydroids on structure (gloves and full exposure protection); low-relief sites can be easy to miss and structures may shift or bury after hurricanes; strong summer thermocline can drop temperatures sharply at depth.

How deep is Blackthorn?

Blackthorn reaches a maximum depth of 24.4 metres (80 feet). It is a saltwater site rated as intermediate difficulty. Depths vary across the site, so plan your profile to your training and verify conditions locally.

Is Blackthorn a shore dive or a boat dive?

Blackthorn is a boat dive — access is by boat rather than from shore. No facilities are recorded at the site, and cell service is recorded as good. Entry details and parking notes, where known, are listed in the access section of this page.

Can beginners dive Blackthorn?

Blackthorn is rated as intermediate difficulty, which may not suit new divers. Listed maximum depth is 24.4 metres (80 feet). Access is by boat. Consider your experience level, conditions, and local guidance before planning.

When is the best time to dive Blackthorn?

May through October offers the calmest seas and clearest water in the northern Gulf; spring water is often murky. Visibility typically 20-60 ft, best in summer. Conditions vary, so check the latest reports and forecasts on the dive site page before your trip.

What will I see at Blackthorn?

Divers at Blackthorn in United States commonly report sightings of Gray triggerfish, Red snapper, Gag grouper, Lionfish (invasive), and Sheepshead. Gray triggerfish, Red snapper, Gag grouper, Lionfish (invasive), and Sheepshead are recorded as common sightings. Marine life varies by season and conditions—check the site page for recent diver observations and photos.

What hazards are recorded at Blackthorn?

Offshore Gulf artificial-reef site: heavy boat and fishing traffic (carry SMB and signaling devices); monofilament line on structure is a common entanglement risk (cutting tool advised); currents magnified around large structures; razor-sharp barnacles and stinging hydroids on structure (gloves and full exposure protection); low-relief sites can be easy to miss and structures may shift or bury after hurricanes; strong summer thermocline can drop temperatures sharply at depth. Hazards and conditions change, so verify current local information before diving.

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