A recent article in Hakai magazine grabbed our attention with its enticing title: “The Secret Language of Ships.” The piece explains the meaning of the various signs and symbols that are printed on the sides of commercial ships. It also includes beautiful photos, worthy of a coffee table book. We recommend taking a look.
Here’s a brief rundown of what those mysterious markings and symbols mean:
IDENTITY INFO: Most commercial ships have the following information on the stern:
- Name of company that owns the ship
- Name of the ship
- Port or “flag” that the ship sails under (70% of commercial ships don’t sail under their own country’s flag!)
- International Maritime Organization (IMO) number
LOAD LINES: The following letters and markings indicate the maximum load a ship can carry:
- A circle with a horizontal line through it: Known as the “Plimsoll line,” it disappears underwater if the ship is carrying too much weight.
- To the right of the circle, another collection of letters and lines shows the maximum load the ship can carry under various climatic conditions (because different condition affect the ship’s buoyancy). Again, if the line disappears underwater, the load is too heavy for that specific weather condition. Here’s what each letter means:
- W = winter temperate seawater
- S = summer temperate seawater
- T = tropical seawater
- F = fresh water
- TF = tropical fresh water
BULBOUS BOW: Some ships are designed with a protrusion low on the bow, which can sometimes be completely submerged. A white symbol that looks the numeral five without the top line (or sometimes, like the numeral three), alerts tugboats to be aware of the “bulbous bow.”
BOW THRUSTER: A white circle with an “X” inside indicates the ship is equipped with a bow thruster, which helps the boat maneuver sideways. The position of the bow thruster is shown as well (e.g. “BT/FP” would indicate a location between the ballast tank and the forepeak).
DRAFT MARKS: Numbers arranged in a vertical line—located on both sides of the ship—measure the distance between the bottom of the hull and the waterline. These numbers can be used to determine if the ship is overloaded and/or listing to one side.
SAFE WORKING LOAD: Tugboats fasten lines to strong posts on a ship, called bitts. White arrows point to the location of the bitts. Letters and numbers next to the bitts indicate the maximum pulling pressure (i.e. “safe working load”) the tug should exert as it helps the ship brake or negotiate docking.
PILOT BOARDING MARK: Just before a ship comes into port, a maritime pilot will ride out to take over for the captain. A white rectangle with a yellow border lets the pilot know where to board the ship.