Key Largo Diving: The Reefs Past Pennekamp’s Three-Mile Line, and the Rules That Changed There

Key Largo’s reef line lies past Pennekamp’s three-mile edge, in federal water

The split is older than the sanctuary. On 15 March 1960, Proclamation 3339 created the Key Largo Coral Reef Preserve and explained its two halves: part of the reef lay “inside the three-mile limit” relinquished to Florida, and “the remainder lies on the sea bed of the outer Continental Shelf”. The inner half became John Pennekamp Coral Reef State Park, dedicated on 10 December 1960 and billed by Florida State Parks as the country’s first undersea park.

The park is a strip, not the whole reef. Its own brochure says it “extends three miles into the Atlantic Ocean” and runs about 21 miles along the coast. The federal half beyond it became the Key Largo National Marine Sanctuary in 1975, and NOAA now calls it the Key Largo Management Area: 146.9 square miles in the sanctuary’s zone data, revised on 28 April 2026, with the attribute “within state waters” set to no.

The reefs that fill Key Largo dive boats sit in that federal half. NOAA’s zone data marks the Carysfort, The Elbow, Key Largo Dry Rocks-Grecian Rocks and Molasses Reef preservation areas as outside state waters. Measured against the Florida Department of Environmental Protection’s own park boundary file, the nearest edge of the Dry Rocks area lies about a kilometer beyond the park line, Molasses about two and Carysfort about three.

That puts the statue in federal water. NOAA says the Dry Rocks area is home to the “Christ of the Deep”, “a 9-foot bronze statue that sits in a sand channel on the offshore side of Key Largo Dry Rocks in less than 25 feet of water”, inside the Key Largo Management Area. A state tourism photograph from about 1985 captions the statue “at John Pennekamp Coral Reef State Park”, and most retellings still do. On the current boundaries, that is wrong.

It matters because of 2025. At Key West the reef preservation areas lie in state waters, where Florida’s governor blocked NOAA’s new sanctuary rule and the 1997 rules still govern. Off Key Largo the reefs are federal, and Keys Weekly reported in March 2026 that NOAA treats the new rule as in force in federal waters since 5 March 2025. The Key West guide sets out that dispute in full; what follows is what it changed here.

The 2025 rule merged two Key Largo reefs, enlarged Carysfort and dropped French Reef

NOAA’s final rule, published on 17 January 2025 as 90 FR 6104, lists the preservation areas from northeast to southwest, and four of the first five are Key Largo dives. Carysfort Reef “is expanded to the 90-foot contour to include additional deep reef habitat”, an addition of 1.6 square miles, which makes it the sanctuary’s largest preservation area at 3.78 square miles. The Elbow and Molasses Reef keep their boundaries.

Key Largo Dry Rocks and Grecian Rocks, one mile apart, were joined into a single area. Some commenters had asked for fishing access in the sand between them, and NOAA cut the zone from the 1.2 square miles in its earlier alternatives to 0.5 square miles “to focus the zone on the high relief reef areas”. NOAA’s page for the combined area puts it at 318 acres.

Anglers asked for trolling in the new deep water at Carysfort, and NOAA refused: an exception for fishing in the expansion areas “would not be compatible with the purpose and intent of SPAs to separate conflicting uses”. Inside every preservation area off Key Largo, NOAA’s zone entries list the same prohibitions: no discharge except cooling water or engine exhaust, no fishing, no removing or possessing marine life, and no touching or standing on living or dead coral.

French Reef went the other way. In its answers to comments, NOAA listed two preservation areas it was eliminating “due to resource condition changes”, Rock Key off Key West and French Reef, and wrote that removing them “removes restrictions on fishing in these areas”. French Reef lies inside the federal management area, so on NOAA’s reading it is now reef that anglers may fish again, under the management area’s gear rules.

The paperwork lags in places. The sanctuary’s preservation area page says there are 17 and lists 16, none of them French Reef. Its public buoy layer, last edited on 11 September 2025, still carries three French Reef SPA boundary buoys beside 20 moorings, one of them for large vessels. A yellow boundary buoy there no longer marks a no-fishing line.

From 19 January 2027 no Key Largo dive boat may anchor in a preservation area

The 2025 rule says “anchoring is prohibited in all SPAs”, and defines anchoring as securing a vessel to the seabed by any means except when using a mooring buoy. NOAA delayed that provision, and the same ban in the restoration areas, until 19 January 2027 to finish a mooring buoy plan. None of the Key Largo areas is among the six exceptions on the sanctuary’s SPA page, and each Key Largo zone entry notes that in 2027 anchoring by any means will be prohibited.

Until then the older wording applies: no anchoring on living or dead coral, and none when a mooring buoy is available. After it, a boat in a preservation area is on a buoy or not attached to the seabed at all.

The sanctuary’s 2025 buoy layer lists 33 moorings at Molasses Reef plus one for large vessels, 15 at Key Largo Dry Rocks, 12 at Grecian Rocks plus one for large vessels, 13 at Carysfort Reef, 8 at Carysfort South and 9 at The Elbow. The buoys are free, first come, first served, and not meant for overnight use.

A second rule waits for the same date. From 2027, a vessel longer than 65 feet may tie only to a buoy designated for large vessels, and a smaller boat may not take one. Until the provision takes effect, NOAA wrote, “large vessels may continue to use regular mooring buoys”.

The wider management area is treated differently on purpose. Commenters objected that a no-anchoring rule across it would hit fishing and that much of it is sand, and NOAA agreed “a no anchor regulation is not needed”. So a boat may still anchor on sand in the 146.9 square miles around the reefs, and not inside the preservation areas it surrounds.

The flag rule in federal water is also the 2025 text. Divers must stay within 300 feet of the divers-down flag on open water and 100 feet in inlets and channels, and boats must hold idle speed with no wake inside those distances and, outside marked channels, within 300 feet of any stationary vessel. The Pennekamp brochure asks snorkelers and divers to fly the flag every time. The state statute that governs flags in state water is covered in the Key West guide.

Turtle Rocks, the one new Key Largo preservation area, was drawn inside the state park

The 2025 rule created only two new preservation areas in the whole sanctuary, and one of them is off North Key Largo. The final rule enlarged Turtle Rocks from 2.3 square miles in the proposal to 2.5 square miles “in order to align this SPA with the existing John Pennekamp Coral Reef State Park marine zone”, and its corner coordinates are printed in appendix F.

Plotted on Florida’s park boundary file, all four corners fall inside Pennekamp, between about a quarter of a kilometer and two kilometers inside the park line. That is state water, and the governor’s certification of 3 March 2025 said the rule would not take effect there. NOAA’s April 2026 zone data contains no Turtle Rocks zone, and its preservation area page does not list one. Its mooring buoy page still names a “Turtle Rocks Sanctuary Preservation Area” among its zones, so NOAA’s own pages do not agree.

What protects Turtle Rocks today is the state. Florida Administrative Code rule 68B-24.0065 names “Turtle Rocks” first among ten areas of Pennekamp, each drawn by four corner coordinates, where no one may take spiny or slipper lobster or set a trap during the regular season, or have either species aboard. The same rule bars lobster harvest from any patch reef anywhere in the park.

The reef itself does not stop at the line. The sanctuary’s buoy layer lists 14 Turtle Rocks buoys, and on the park boundary file 5 of them sit inside Pennekamp and 9 outside it, in the federal management area. Two boats on the same reef can be under different rulebooks.

Diving from Pennekamp’s own docks: Key Largo’s park fees, lobster closures and speargun ban

Many first Key Largo dives start at the park itself. Its fee page lists $8 per vehicle plus 50 cents per person for up to eight people, $4.50 for a single-occupant vehicle and $2.50 per pedestrian or cyclist, and $10 per vessel to launch a boat for the day. Hours are 8 a.m. until sunset, 365 days a year. Admission is not guaranteed once the parking is full.

The trips are sold by the park concession. The park describes glass-bottom boats three times a day and snorkel boats four times a day, each 2.5 hours with about 1.5 hours on the reef, and four-hour scuba trips with two tanks at two locations. Coral Reef Park Company has run those services since 1963, according to the park. Given the boundaries above, a trip sold at the park can end on reef the park does not manage.

Two notices on the park page, as archived on 24 August 2026, are worth checking before a visit. A Florida Department of Health beach water advisory for elevated enterococci bacteria in nearshore waters took effect on 13 August 2026. Construction since 22 July 2026 has closed one of the two boat ramps and the boat sewage pump-out station and cut boat trailer parking. The live page refused automated requests on 24 September 2026, so neither notice could be confirmed as current.

The park’s brochure is short on rules and clear about them. Touching or standing on corals “may kill them and is therefore prohibited”. Spearfishing is prohibited, tropical fish may not be collected, and “no lobster may be harvested from or within any coral formation”. During Florida’s two-day lobster sport season, the last Wednesday and Thursday of July, rule 68B-24.0065 closes the whole park to lobster harvest and bans possessing lobster aboard any vessel from which someone is diving there.

Beyond the park, the federal rule goes further on spearguns. Across the Key Largo Management Area, 15 CFR 922.164(b) prohibits “fishing with, carrying, or possessing” pole spears, Hawaiian slings, pneumatic guns “or similar devices known as spearguns”, and bans collecting tropical fish. Recreational lobster by hand or hand gear remains allowed there. The 1960 Interior Department rules for the preserve, 43 CFR Part 15, are still printed in the federal code and say it more warmly: diving “for observation and pleasure is permitted and encouraged”.

The Spiegel Grove took Key Largo divers off the natural reefs, and the Vandenberg did not

The big wreck off Key Largo is a former Navy landing ship. The Florida Fish and Wildlife Conservation Commission files the Spiegel Grove as a 510-foot LSD-32 of 6,880 tons in 135 feet of water with 84 feet of relief, under federal jurisdiction, deployed on 17 May 2002. The same record adds “Pushed on Side on 6/10/02”. It lies inside the Key Largo Management Area, and the sanctuary keeps ten wreck moorings on it.

The sinking did not go to plan. NOAA’s condition report says the ship “landed upside down upon sinking”, that an “unplanned, unfunded salvage effort” moved it onto its starboard side, and that Hurricane Dennis in July 2005 “righted the ship to its originally intended position”. NOAA’s study dates the sinking to June 2002; the state record keeps the May date for the deployment and June for the roll.

The Key Largo Chamber of Commerce organized the sinking to bring in dive business, and NOAA tested a second promise: that a new wreck would take pressure off the natural reefs. Researchers used dive shop logbooks and on-water counts for ten months before and ten months after. Total use of the surrounding natural reefs fell 13.7 percent, and scuba dives on them fell 12.7 percent, or 17,834 dives. The natural reefs’ share of use dropped from 86.8 to 68.5 percent.

The authors flagged two limits: the data left out June and July, about a quarter of the year’s reef use, and the pattern might be the novelty of a new wreck. It is still the opposite of Key West. There, NOAA found scuba diving on the natural reefs rose after the Vandenberg went down, and its own summary says the Vandenberg, “unlike the Spiegel Grove, did not reduce user pressure”. The Key West guide has those numbers.

Two older wrecks sit south of Molasses. The Coast Guard cutters Duane and Bibb, both 327 feet, were sunk on 27 November 1987. NOAA puts the Duane upright in 120 feet of water, one mile south of Molasses Reef, with the crow’s nest at 60 feet, the bridge at 70, the superstructure deck at 90 and the main deck at 100; the Duane is listed in the National Register of Historic Places. The state files the Bibb on its starboard side at 130 feet, 95 feet to the rail.

Both lie just outside the Key Largo Management Area: on NOAA’s boundary and the state’s coordinates, the Bibb sits about 1.2 kilometers and the Duane about 1.8 kilometers beyond its line. The buoy layer lists three moorings on the Duane and two on the Bibb. At these depths gas planning matters, and our nitrox explainer covers what a mix changes; the wreck diving list covers other coasts built on sunk steel.

Carysfort and Horseshoe off Key Largo kept living staghorn through the 2023 heat

A 2024 study calls the summer of 2023 the most severe on record for Florida’s Coral Reef. The sanctuary recorded warm water from February, the longest-lasting marine heat wave in the region since 1991, and a BleachWatch alert on 28 July 2023 warning that significant bleaching was expected and mortality likely. NOAA called them the hottest ocean temperatures on record for the Keys.

Key Largo’s outer reefs had it easier than most. A study published in December 2024 tracked more than 4,200 brain and boulder corals at nine reefs from Sand Key to Carysfort. At seven of the nine, only 0 to 2 percent of colonies suffered any mortality, and Carysfort had none. Across the years since 1985 in which heat stress crossed the 4 degree heating week threshold, the authors found Grecian/Key Largo Dry Rocks and Carysfort “consistently the coolest” of their sites.

The branching corals fared worse. The same authors report seeing local extinctions of Acroporid corals at most of their sites. A NOAA survey in February 2024 of five Mission: Iconic Reefs sites found that less than 22 percent of about 1,500 outplanted staghorn corals were still alive, and only the two northernmost reefs surveyed, Carysfort Reef and Horseshoe Reef, both off Key Largo, had any living staghorn. Carysfort was also one of three sites with live elkhorn.

Both are restoration sites. NOAA’s plan for Carysfort calls it the largest demonstration site for elkhorn and staghorn restoration in the Keys, with more than 200,000 corals to be outplanted; Horseshoe is to get more than 75,000. Horseshoe’s NOAA site sheet says its two mooring buoys “support recreational fishing and diving”. The sheet predates the 2025 rule: the 219.7-acre Horseshoe Reef Habitat Restoration Area applies the preservation-area prohibitions, and NOAA’s zone data marks fishing there as not allowed.

The coral nurseries are closed to stopping. NOAA’s zone data lists Nursery Restoration Areas at Carysfort Reef, Key Largo, The Elbow and Tavernier, all federal, where entering is prohibited “except for continuous transit without interruption”: a dive boat may cross one, not stop in it. Coral Restoration Foundation, based in Tavernier, describes its Tavernier Coral Tree Nursery as an acre and a half of seafloor with more than 500 coral trees. The Miami guide traces the coral disease that hit these reefs before the heat.

Seven Key Largo dive businesses in the registers, two of them filed in Tavernier and Islamorada

The Key Largo operator list holds 7 businesses. Six are published by SSI in its register of affiliated training centers, read on 20 September 2026: Conch Republic Divers, Horizon Divers, Key Dives, Ocean First Key Largo, Quiescence Diving Services and Sea Dwellers Dive Center. Two, Key Dives and Silent World Dive Center, are Green Fins digital members, read on 14 August 2026 and self-evaluated rather than assessed in person. All seven publish a website.

The register’s town field shows how far “Key Largo” stretches. SSI files four of its six entries in Key Largo, Conch Republic Divers in Tavernier and Key Dives in Islamorada. Where a business is filed is not where its boats go, and every one of them reaches the same federal reefs described above.

SSI rates Horizon Divers for Extended Range and Rebreather, and Conch Republic Divers, Key Dives and Ocean First for Freediving. Silent World’s own website names PADI. A rating is a listing, not evidence that a course runs this season, and these are membership registers rather than licenses; which registers can be read sets out what each returns. Treatment cover for deep wreck diving is a separate purchase, which the dive insurance comparison covers.