It's the Law

Diving and Snorkeling Activities


Diver-Down Flag

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 flag on federal waters.

Except in the case of an 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.

Divers Flag

A rectangular red flag, at least 12 x 15 inches with a three-inch white diagonal stripe, mounted on a float or buoy to be clearly visible

Alfa Flag

A blue and white International Code Flag A (or Alfa flag), usually flown from a vessel and used on federally controlled waters

Divers and Alfa flags
Divers and Alfa flags

Diving Around Wisconsin’s Historic Shipwrecks

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.