Hawk Channel is a shallow, elongatedbasin andnavigable passage along theAtlantic coast of theFlorida Keys. The channel makes up a smaller portion of theFlorida Platform fromKey West to the southernmost point ofKey Biscayne and lies between the Keys and theFlorida Reef Tract to the southeast.[1] It connects the waters of theGulf of Mexico to the Atlantic Ocean throughtidal exchanges crossing from theFlorida Bay to theStraits of Florida.[2][3][4]
It extends roughly 230 km (120 nmi; 140 mi) fromFowey Rocks, off Key Biscayne, toSand Key, off Key West. Its width ranges from approximately 10 km (5.4 nmi; 6.2 mi) to 0.40 km (1⁄4 mi) wide at its narrowest part.[5][6] It varies in depth from 7 to 8 m (23 to 26 ft) off the Upper Keys along the center of the channel to 12 to 15 m (39 to 49 ft) off the Middle and Lower Keys. Acourse in Hawk Channel roughly 3.2 km (2 mi) offshore is partially protected by the deepwater of the Straits of Florida and allows vesselsdrawing roughly 2.1 to 3.0 m (7 to 10 ft) to avoid the adversecurrents of theGulf Stream while crossing through the Keys.[7][8][9]
24°47′N80°47′W / 24.783°N 80.783°W /24.783; -80.783
Hawk Channel has an orientation parallel to theFlorida Keys and serves as thecontinental shelf for the Florida KeysAtlantic side. It lies south or southeast between the mainland keys and an extensive reef tract 8 km (4.3 nmi; 5.0 mi) offshore. The Florida Reef Tract, a band of coral reefs along the southeast side of the Florida Keys, is located on a narrow shelf that drops off at theFlorida Straits and slopes seaward at a 0.06 degree angle into Hawk Channel. Asand ridge lying between Hawk Channel known as "White Bank" is the closest of the two ridges off of the Reef Tract and is subject to open tidal exchanges with the Atlantic. The passage is considered a dividing-line betweeninshore non-reef and offshore reef areas.[10]
The warm, nutrient-deficient waters that circulate through this exchange are conducive to the development of patch reefs 3 to 6 m (9.8 to 19.7 ft) deep off of Hawk Channel.[11] The course along the channel is partially protected by a fringing barrier reef roughly 3 to 6 mi (4.8 to 9.7 km) offshore, limiting the effects of winds bearing northwest and sheltering the passage from the direct thrust of the Atlantic and Florida Straits.[12] The four central exchanges ofSouth Florida coastal waters of Long Key Channel, Channel 5, Channel 2, andMoser Channel, situated perpendicular to the Keys, produce a current of up to 3 to 4knots (5.6 to 7.4 km/h; 3.5 to 4.6 mph).
Vessels will often usebeacons on the Florida Reef as guides in order to navigate through the entrance of Hawk Channel beginning 10 mi (8.7 nmi; 16 km) south ofMiami'sGovernment Cut and 3 mi (2.6 nmi; 4.8 km) south of the southern tip of Key Biscayne, with the crossover between and Biscayne Bay averaging about 4.5 ft (1.4 m) inmean low water (mlw). Most non-commercial vessels may avoid Hawk Channel due to effects of local currents and considerablecommercial traffic in theGulf Stream. Roughly 53 mi (85 km) south of Fowey Rocks, the channel cuts throughJohn Pennekamp State Park, the adjacentfederal sanctuary, andHens and Chickens reef passed the 33 mi (53 km) length ofKey Largo before continuing next 30 mi (26 nmi; 48 km) to Key West.[13][14] Hawk Channel provides comparatively smooth waters protected from Gulf Streampowered winds except when passing through the substantial openings in the fringing reefs found 61 mi (98 km) betweenAlligator Reef Light andAmerican Shoal Light. According to marine reports, the local current predominately sets fair with the channel except alongside the opening between Hawk Channel and Biscayne Bay where fairly strong crosscurrents exist most notably during anebb tide.[15]
The channel runs systemically with theFlorida Current pushing water northward from the Atlantic with a velocity of 1.8 m/s (3.5 kn) and a mean transport of 30Sv. Hawk Channel'socean floor also makes up the easternescarpment of theFlorida Platform where theFlorida Peninsula lies 3 to 4 mi (4.8 to 6.4 km) from the platform's edge. Sand Key Light, the marker indicating the southernmost portion of the channel, is located 6 nmi (11 km; 6.9 mi) southwest of Key West, between Sand Key Channel and Rock Key Channel, two of the channels into Key West, on a small sand covered reef.[16][17] Hawk Channel contains an estimated 1,000 or moreshipwrecks in its waters. A populardivingtrail consisting of nine notable wrecks along the channel are designated as "Shipwreck Trail" under theFlorida Keys National Marine Sanctuary.[18][19]
Although the exact origins of the name remain largely uncertain, Hawk Channel has been a prominent site forbirdwatching; the prolongedbird migration in thefall season goes on from early July until late November where large flights ofbroad-winged hawks, as well asmerlins, andperegrine falcons, are predominant during the September–October migration.[20]
Prior to theSpanish occupation of Florida, the Florida Keys and its surrounding waters, including Hawk Channel, were inhabited by theCalusa andTequesta tribes. On15 May 1513, the Spanish explorer,Juan Ponce de León, and his fleet sailed south from Biscayne Bay along Hawk Channel through the Florida Keys. While charting the surrounding waters, he named the islandsLos Martires ("The Martyrs"), as they reminded him of suffering men from a distance.[21]
Beginning as early as the 16th century, numerousmerchant ships wrecked off of the shallow reefs of Hawk Channel while sailing along notable shipping lanes within the Gulf Stream, expanding the prosperouswrecking industry off of the Southern coast of the Keys. Increasing revenues brought the islands' first settlements in 1822, bringing thefishing industry's use of the passage with it. In 1733, ahurricane wrecked 19 ships of theSpanish treasure fleet on Florida Reef along Hawk Channel. The remaining survivors camped on the nearbyIndian Key until they were rescued.
With the construction ofHenry Flagler'sOverseas Railroad in 1905, four predominant channel passages were dredged perpendicular to the Keys and the railroad's various bridge extensions, including Moser Channel through theSeven Mile Bridge. These channels allowed the passage of boats and tidal exchanges from the Florida Bay and theIntercostal Waterway into Hawk Channel. Additional channels include Long Key Channel, Channel 5, and Channel 2.[22]
In November 1822, theUSS Alligator ran aground on a shallow reef off of Hawk Channel while escorting aconvoy of merchant vessels. The United States later sank her in order to prevent its remains from beingsalvaged bypirates. The wreck lies 4 nautical miles (7.4 km; 4.6 mi) east of Indian Key, near the Matecumbe Keys, north ofAlligator Reef itself, and is marked by theAlligator Reef Lighthouse.[23]
In June 1748, theRoyal Navy frigateHMS Fowey struck a reef off of Hawk Channel. She sank on 26 June. A few miles south ofCape Florida, the Fowey Rocks Lighthouse, named after the frigate, was constructed in 1878. While construction was still underway, theSS Arratoon Apcar ran aground on the reef.
In 1858, theSombrero Key Light, the tallest lighthouse in the Florida Keys, was put in service located on a mostly submergedreef that had been referenced in oldSpanish charts but had eroded away during the 19th century. The lighthouse now lies near theSombrero Key Reef.
Between 1921 and 1935, theunmanned reef lights ofMolasses Reef Light,Pacific Reef Light,Hen and Chickens Shoal Light, Smith Shoal Light, andTennessee Reef Light were erected as navigational aids andDaymarks along Hawk Channel to mark shallow hazards.[24]
On 4 August 1984, the motor vesselWellwood ran aground on the upper fore-reef on Molasses Reef southeast off ofKey Largo in 6 metres of water, resulting in the destruction of 5,805 square meters of living corals. The wreck remained grounded for 12 days before it was removed by theU.S. Coast Guard.[25]