Metal parts underwater are subjected to two basic types of corrosion: galvanic corrosion and stray current corrosion. Both can harm your boat, propeller, and motor if not correctly monitored and avoided.
According to Flags Unlimited, the significance of the flag's colors is this: The Blue represents the officer and the courage they find deep inside when faced with insurmountable odds. The Black background was designed as a constant reminder of our fallen brother and sister officers.
Blue - Vigilance, perseverance, and justice. Red, white and blue is a very common color combination for flags around the world. Probably the most important connection is to the Union Jack -- the flag of the United Kingdom.