Diving and Snorkeling From a Boat in Florida

Florida's reefs, wrecks and clear springs-fed waters make diving and snorkeling from your own boat one of the best ways to see the state. This page covers the Florida rules for divers-down flags, what other boaters must do when they see one, how to use reef mooring buoys in the Florida Keys, and the safety habits that keep divers and boat tenders out of trouble.

Divers-down flag rules in Florida

Florida's divers-down rules are in section 327.331 of the Florida Statutes. They apply to scuba divers and snorkelers alike: the law defines a diver as a person wholly or partially submerged and equipped with a face mask and snorkel or underwater breathing apparatus.

What counts as a divers-down warning device

The divers-down symbol is red with a white diagonal stripe. A warning device can be a flag, a buoy or a similar device, and it must be prominently visible when in use. The symbol must measure at least:

Where it is displayed	Minimum symbol size
From the water (for example, a float towed by a diver)	12 x 12 inches
From a vessel	20 x 24 inches

A divers-down flag must have a wire or other stiffener so it stays fully unfurled when there is no wind. A divers-down buoy may not be used or displayed on board a vessel; on the boat, use a flag.

When and where to display it

• Always while divers are down. Divers must display a warning device in the area where they dive, unless they are in an area customarily used only for swimming.
• From the highest point of the boat, or another spot where it is visible from every direction.
• Only while divers are in the water. Take the flag down once everyone is aboard or ashore. You may not operate a boat displaying the flag unless it has divers in the water.
• Not as a hazard. On rivers, inlets and navigation channels, divers may not display flags in a way that unreasonably blocks navigation, except in an emergency.

How close divers should stay to the flag

Divers must make reasonable efforts to stay within 300 feet of their warning device in open water, and within 100 feet on rivers, inlets and navigation channels.

What boat operators must do near a dive flag

Every boater in Florida, diving or not, needs to recognize the flag and react. The same section of law sets your duties as an operator:

• Keep your distance. Make a reasonable effort to stay at least 300 feet from a divers-down device in open water, and at least 100 feet on rivers, inlets and navigation channels.
• Slow down if you must pass closer. Inside those distances, a vessel other than a law enforcement or rescue vessel must go no faster than needed to maintain headway and steerageway.
• Watch for bubbles and snorkels, not just the flag. Divers can surface away from it.

Inside the Florida Keys National Marine Sanctuary, sanctuary rules add a requirement of idle speed and no wake within 300 feet (100 yards) of a divers-down flag. For broader right-of-way rules, see Navigation Rules.

Reef mooring buoys and anchoring in the Florida Keys

The Florida Keys are home to the Florida Keys National Marine Sanctuary, managed by NOAA. Its rules protect the coral reef that most Keys dive and snorkel trips visit.

Using sanctuary mooring buoys

According to the sanctuary, mooring buoys have been used in the Keys since 1981 as an alternative to anchoring, which can break and damage coral. Sanctuary mooring buoys are white spheres with a blue stripe. More than 600 are available on a first-come, first-served basis at no cost.

• Standard 18-inch buoys support vessels up to 59 feet.
• Larger 24-inch buoys are for vessels from 60 to 100 feet and are found only at certain sites, such as some large wrecks and preservation areas.
• Yellow buoys mark zone boundaries. They have no mooring lines, and you may not tie up to them.

If every buoy at a site is taken, wait or go elsewhere. Mooring fields in Keys anchorages may charge a fee; the reef buoys maintained by the sanctuary do not.

Anchoring rules

Anchoring on living coral is prohibited throughout the sanctuary. If no mooring buoy is available and you are outside a no-anchor zone, the sanctuary says you may anchor in sandy areas away from coral and seagrass. Never let your anchor, chain or hull drag across the reef, and watch your depth: running aground or prop scarring seagrass is also prohibited.

Protected areas and what you can take

The sanctuary uses marine zones with different levels of protection. In sanctuary preservation areas and conservation areas, fishing by any means is prohibited, as is touching, standing on or taking coral, shells or marine life. Sanctuary-wide, it is prohibited to remove or injure coral or live rock, to feed fish from a boat or while diving, and to dive or snorkel without a dive flag.

Zone boundaries are marked by yellow buoys. Check the sanctuary's zone maps before you go, because the rules depend on exactly where you stop. Outside the Keys, state parks, aquatic preserves and manatee zones carry their own rules; see Environmental Rules.

Spearfishing and collecting

Spearfishing, lobstering and collecting marine life are fishing activities. They require the right FWC fishing license and are subject to species rules, seasons and closed areas, including areas where spearing is not allowed, such as sanctuary preservation areas in the Keys. Rules change often, so check FWC's saltwater fishing regulations (opens in a new tab) before every trip and read our Fishing in Florida overview.

Dive and snorkel safety from your boat

On a private boat, you are the dive operator. Separation, current and boat traffic are the hazards to plan for, along with your gear.

Buddies and the boat tender

Dive and snorkel with a buddy, and stay close enough to help each other. Leave at least one capable person on the boat whose only job is to watch the divers, the flag and the weather. That tender should know how to start the engine, pick up divers safely and call for help on VHF channel 16; see Boating Emergencies.

Current and drift diving

Florida's Atlantic reefs can have strong current. On a drift dive, the boat follows the divers rather than staying moored, and divers tow a surface float with a divers-down flag so the boat and other traffic can track them. Approach divers slowly with the engine in neutral as you get close, and never back toward people in the water. Divers should carry a surface signal device, such as an inflatable marker, in case they surface far from the boat.

Frequently asked questions

How far must I stay from a divers-down flag in Florida?

Florida law asks boat operators to make a reasonable effort to stay at least 300 feet away in open water and at least 100 feet away on rivers, inlets and navigation channels. Inside those distances, slow to the speed needed to keep headway and steer.

Do snorkelers need a dive flag in Florida?

Yes. Under Florida law a diver includes anyone in the water with a mask and snorkel, and divers must display a divers-down warning device, except in areas customarily used only for swimming.

Can I leave my dive flag up after everyone is back on board?

No. Florida law says the flag may not be displayed once all divers are aboard or ashore, and you may not run a boat displaying it unless divers are in the water.

Can I anchor on the reef in the Florida Keys?

No. Anchoring on living coral is prohibited in the Florida Keys National Marine Sanctuary. Use a sanctuary mooring buoy, or anchor in sand away from coral and seagrass where anchoring is allowed.

Official sources

1. Florida Statutes s. 327.331 — Divers; divers-down warning device required (opens in a new tab)
2. Florida Keys National Marine Sanctuary — Regulations (opens in a new tab)
3. Florida Keys National Marine Sanctuary — Buoy Program (opens in a new tab)
4. Florida Keys National Marine Sanctuary — Marine Zones (opens in a new tab)

Checked against these sources on October 2, 2026. Rules change — confirm current requirements with the official source before you rely on them.