Blue flags suggest the water is good and clean.
Green flags mean it is safe to swim and supervised.
Orange flags indicate an area where swimming is authorised but with precaution.
Red flags indicates a dangerous area where swimming forbidden.
Yellow flags indicate that the water is polluted.
Yellow buoys mark out channels; Spherical for the swimming areas, Cylindrical for cross channels (where boats come through).
The large flat and often windy beaches of North France are ideal for sailing and sand yatching.
Surfing - includes storm spankers, catamarans, wind surf boards and kite surfing.
Beach Craft - pedal boats, surf boards, inflatable boats or other boats.
General Rules;
As with powered craft you must reduce your speed to 5 knots when inside the 300m beach zone.
Never go further than 2 nautical miles from the beach with a storm spanker, 1 mile on a wind surf board, and 300m on a beach craft.
Do not overestimate your physical capabilities or those of your equipment.
Sail as part of a group where possible.
Beware of winds pushing you away from the coast.
Use a wet suit and a harness.
Do not try and force your right of way - take care not to get in the way of shipping.
If you want to learn to sail use either a Fédération Francaise de Voile (Yachting Club), or a club affiliated to the École Francaise de Voile, which offers organised courses with qualified teachers.