Divers-down flags and the distance to keep
Make a reasonable effort to keep at least 300 feet from a divers-down warning device in open water, and at least 100 feet on rivers, inlets and navigation channels.
Two distances, one wording
Florida measures from the divers-down warning device, and it gives two distances: at least 300 feet on water other than a river, inlet or navigation channel, and at least 100 feet on a river, inlet or navigation channel. The Keys and the reef line are full of both — a channel marker to starboard and open water to port, with the same flag in sight.
What matters as much as the figures is how the section words the duty: a person operating a vessel must make a reasonable effort to maintain the distance. That is not a prohibition with a hard edge, and it is not a licence either. In a narrow channel where 100 feet is the whole width, “reasonable effort” is doing the thinking, and it tends to mean idle speed and a wide berth rather than a measurement.
The sizes, in the statute’s own terms
A device displayed from a vessel is at least 20 by 24 inches. A device displayed from the water is at least 12 by 12 inches. The second one is usually quoted as the size of a buoy, which is probably what it means and is not what it says — and the section separately forbids using or displaying a buoy onboard a vessel.
For a visiting crew the practical reading is simple: if you tow a float while snorkelling, it carries the smaller flag; the one on the backstay is the bigger one.
Worth knowing
- A reasonable effort, not a fence. Both distances are written the same way: a person operating a vessel must make a reasonable effort to maintain a distance of at least 300 feet, or at least 100 feet on a river, inlet or navigation channel. The section does not word either as a flat prohibition, and this page does not harden it into one.F.S. 327.331
- "From the water", not "on a buoy". The smaller size belongs to a device displayed from the water; the larger one to a device displayed from a vessel. Separately, the section says a buoy may not be used or displayed onboard a vessel. "A buoy is 12 by 12 inches" is a reasonable guess and still a guess.F.S. 327.331
- The distance is measured to the device, not to a diver. What the section measures from is the divers-down warning device. Where the diver actually is, nobody on deck can know.F.S. 327.331
Questions
How far do I have to stay from a divers-down flag in Florida?
On water other than a river, inlet or navigation channel, a reasonable effort to maintain at least 300 feet. On a river, inlet or navigation channel, at least 100 feet. Both are measured from the divers-down warning device.
Is 300 feet an absolute limit?
The statute does not word it that way. It asks the operator of a vessel to make a reasonable effort to maintain the distance — which is a different test from a line on a chart, and a reason to slow down early rather than argue about feet.
How big does the flag have to be?
At least 20 by 24 inches when displayed from a vessel, and at least 12 by 12 inches when displayed from the water.
May I carry a divers-down buoy on deck?
The section says a buoy may not be used or displayed onboard a vessel. What size a buoy in the water has to be, it does not say in those words — it gives the size for a device displayed from the water.