Rideau Canal flags (Canada)

The Rideau Canal is probably as famous for it's "world's longest skating rink" which is made every winter in Ottawa.

It is interesting to note on the Rideau Canal website documents the use of flags to indicate the ice conditions:

Winter Flag System

The National Capital Commission uses a flag system to indicate canal conditions. Flags are located at the shelters on the canal. Green Flags indicate good conditions, yellow flags indicates fair to good conditions, and a red flag means the ice is not safe and the canal is closed.

Rob Raeside, 17 July 2007

Two flags (10" x 15") with the same design but different color schemes (bronze and silver) are offered for sale at the rideau175.org website.
Darrell Neuman, 17 July 2007