Located 4 nautical miles off Marathon and 3.5 miles southeast of Key Colony Beach in 15-30 feet of water, this small series of patch reefs has some rare pillar coral and some of the largest brain corals in the Keys.
Anchor 50 yards east or west of the 6 foot piling that marks the site. This site is a great beginner/novice dive site.
This location was named for a ship that wrecked here that was carrying a load of coffins. (via Adiscuba)
Coffins Patch Marathon Wiki
Coffins Patch is a shallow coral reef (patch reef) located within the Florida Keys National Marine Sanctuary. It lies to the southeast of Bamboo Key. This reef lies within a Sanctuary Preservation Area (SPA).
The wreck is not visible but the beautiful corals and plentiful marine life make this a great shallow water dive and photographic opportunity.
Beware of FIRE CORAL in the area. This site is a SPA area where no fishing, collecting or lobstering is allowed.
The northeast side has some of the largest brain corals found in the Keys.
There is also a favorite section called the Doughnut. This is a circular section of about a 100 yard diameter filled with tropicals and curious fish who may follow divers around.