- Boats not involved with the diving operation must remain 150 feet away from a flag.
- No more than four divers shall dive under one flag.
- Divers must remain within 50 feet (measured horizontally) of the warning flag.
- If a group of divers is using a contained area, the perimeter of the area must be marked. The area must be outside the normal area of navigation. These markings must consist of the official diver’s flag and must be placed around the perimeter of the diving area at intervals of not more than 150 feet.
- Persons who dive from one hour after sunset to sunrise on the following day must carry a diver’s light visible when above the water for a distance of 150 feet.
- Scuba or skin diving while in possession of a spear is unlawful from sunset to sunrise.
- Do not place a diver’s flag where it will obstruct navigation.
- Must measure at least 15 inches horizontally and 12 inches vertically.
- Both sides must have a red‑colored background bisected diagonally by a 3‑inch wide white stripe.
- There is also a blue and white diver’s flag authorized under the federal rules of the road.
The diver’s flag may be displayed on a watercraft or float or be anchored to the bottom. The top of the flag must be at least 30 inches above the surface, however.

According to the Wisconsin Boating Laws and Responsibilities Handbook, Approved by the Wisconsin Department of Natural Resources

Please check for requirement updates before diving

The purpose of a diver-down flag is to warn boaters to
avoid the area where divers are under water.
■ It is unlawful to engage in underwater skin diving or swimming with the use of swimming fins outside a marked swim area or beyond 150 feet from shore unless the location of such swimming or diving is marked by a divers flag.
■ It is unlawful to scuba dive outside a marked swim area unless the location of the scuba diving is marked by a divers flag.
■ A diver must stay within 50 feet of the diver-down flag on federal waters.
■ Except in case of emergency, anyone engaged in such swimming or diving shall not rise to the surface outside of 50 feet from divers flag.
■ No person diving or swimming shall interfere with someone engaged in fishing.
■ No person shall dive or swim in any established navigation lane.
■ It is unlawful to display a diver-down flag when not diving.
■ Vessels not engaged in diving operations must stay at least 100 feet away from any displayed diver-down flag.
■ Two types of flags are used to indicate diving activity
The Wisconsin Historical Society has published information about many historic shipwreck sites in Wisconsin waters, some of which are marked by seasonal mooring buoys. Damaging or removing material from a wreck site not only diminishes the enjoyment for future visitors but also is a crime that can result in fines; imprisonment; and the loss of a diver’s gear, boat, trailer, and vehicle

Local Diving

2026 Local Diving Schedule