The Handbook of Iowa Boating Laws and Responsibilities
The Official Boating Handbook of the Iowa Department of Natural Resources - Web Version
Table of Contents
Scuba divers, skin divers, and snorkelers must display a diver-down flag that marks their diving area.
Vessels not engaged in diving operations must stay at least 50 feet away from a displayed diver-down flag.
Two types of flags are used to indicate diving activity.
A rectangular red flag with a white diagonal stripe, attached to a vessel, float, or buoy
A blue and white International Code Flag A (or Alfa flag), flown from a vessel