Sand Key Lighthouse standing on its iron legs in shallow turquoise water

Key West · United States · Reef

Sand Key

An eroded island's sand patch ringed by shallow reef under Sand Key Light

Photo: NOAA Photo Library · Public domain

Sand Key was originally an island. Erosion and hurricanes have reduced it to a very small patch of sand ringed by coral reef beneath Sand Key Lighthouse, southwest of Key West in Hawk Channel. The reef summit lies between 1 and 35 ft (0.3 and 11 m) and the site is a no-take Sanctuary Preservation Area of the Florida Keys National Marine Sanctuary, dived and snorkelled from boats over a sand patch that most Florida reefs do not have.

Also known as Sand Key Lighthouse, Sand Key Reef.

Where it is and how deep

Depth profile of Sand Key: typical dive 0.3–11 m (1–36 ft) 18 m · Open Water30 m · Advanced40 m · Recreational limit0.3 m11 mtypical dive
Depths on a shared scale to 40 m (130 ft); dashed lines mark common certification limits.

24.4542° N, 81.8778° WPublished position for this site.

The dive

You go in beside Sand Key Lighthouse over what used to be an island; the reef lies to the south of the light. Erosion and hurricanes have cut Sand Key down to a very small patch of sand ringed by coral reef, and the reef summit lies anywhere from 1 to 35 ft (0.3 to 11 m), so the profile is set by where on the reef you choose to swim rather than by your gas. Pick a depth on the reef edge and work around the sand patch; at these depths the dive is long and bright, and nothing about it needs a deep plan.

The sand is the feature you rarely get on other Florida coral reefs, and it is what makes Sand Key as much a snorkel stop as a dive. Sand Key falls within a Sanctuary Preservation Area of the Florida Keys National Marine Sanctuary; the sanctuary's 2025 Restoration Blueprint rule kept the SPA unchanged and removed its old exception for catch-and-release trolling, so the zone is now fully no-take. You finish where you started, ascending up the shallow reef edge to the boat with the lighthouse still in view.

Marine life and season

The sources we used don't single out particular species here.

Month-by-month season rating for Sand Key
JanFebMarAprMayJunJulAugSepOctNovDec
FairFairGoodPrimePrimeGoodGoodGoodFairFairGoodGood

Season follows Key West: November-April is the dry season, but winter cold fronts bring the coolest water (23 C) and the lowest sourced visibility; the wet season runs May-October and storm risk peaks in September.

Photos from Sand Key

  • Florida Keys--Public Libraries from Key West, Fla., USA · CC BY 2.0

  • SNORKELINGDIVES.COM · CC BY 2.0

Questions divers ask

How deep is the Sand Key reef?+

The reef summit runs from 1 to 35 ft (0.3 to 11 m), so Sand Key is a shallow dive well within Open Water depth limits.

Is Sand Key a protected area?+

Yes. The reef falls within a Sanctuary Preservation Area (SPA) inside the Florida Keys National Marine Sanctuary, kept unchanged by the 2025 Restoration Blueprint rule, which also removed the SPA's catch-and-release trolling exception.

Sources

  1. Sand Key (reef) — Wikipedia
  2. Sand Key Lighthouse — Scubago

Photo credits

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