Flag usage is widespread from national flags and state flags to organizational flags and even decorative flags, but at sea, a flag has many more uses and can actually save lives. Flags even have different meanings at sea and different uses than they do on land, so it’s important to understand the etiquette and proper use of flags at sea.
First, if you are flying a national flag at sea, it is known as an ensign rather than a nautical flag. In some instances, a country may employ a different flag design for their ensign, where in others they will use their standard national flag. Ensigns are most commonly flown by yachts, merchant ships and other commercial sea vessels. According to proper etiquette if you fly your national ensign, you should also fly the flag of the waters, and or nation to which you are visiting. In older times, if you flew only your national flag from your ensign staff, you were indicating a willingness to fight or go to battle. In fact, this etiquette is still taken very seriously in foreign ports.
In addition to national ensigns, there are also designated national merchant ensigns, battle ensigns and even yacht ensigns, and in many countries, without the proper flag, you can be subject to civil penalties for miscommunication. For instance if you are sailing in a yacht and you have cargo on board, but you do not fly a merchant ensign, you may be accused of nefarious behavior.
In some countries, there are not multiple ensigns then this becomes somewhat irrelevant, for example in the United States the merchant ensign, the yacht ensign or yacht flag and the national ensign are all one in the same: the U.S. national flag. No matter what, you typically have to fly an ensign, the proper one for your purpose, when entering or leaving any harbor or when traveling in foreign waters.
Historically, flags or ensigns of honor were flown from the ships stern, or the rear of the ship. Today ensigns are often flown from the yard-arm or from the mast but unlike on land, the flag flown from the stern maintains its level of superiority over any other flags flown on the ship, despite height. Additionally, at sea, when you fly your national ensign, you are supposed to “dip” it when passing another ship as a sign of friendly etiquette.
Other flags flown frequently are naval Jacks, which are specific national flags, designed for sea. They are not flown while a ship or boat is underway in the water, but rather are flown when a ship is in port or participating in a naval parade or other ceremonial occasion.
Naval ships also may fly rank flags, which denote which ship is carrying the superior officer and it is from this tradition that the term “flag ship” was born. Pennants can also be flown, indicating not only when a ship or captain was commissioned into the navy, but also if an officer is on board, to signify if a Sunday service is occurring and other such events onboard the ship.
The burgee is another traditional nautical flag, triangular in shape, and is often used by clubs to signify membership and also to identify special citations a ship may have received in battle. Finally,international maritime signal flags are also still used regularly today throughout the world. While each flag symbolizes a letter, each also has a meaning of its own.