Okay, let's all get it out of our systems right now. The poop deck of a sailing ship has absolutely no connection with a certain bodily function. That sort of business is generally handled in the area below the ship's bow called the head. A poop deck is actually the roof of a poop cabin located in the rear (aft) section of a sailing ship's main deck.
The word poop for our purposes comes from the Latin puppis, meaning "stern." Shipbuilders often designed a cabin space in the very rear of the ship called a poop cabin. This poop cabin extends a few feet above the level of the main deck, and is finished off with a flat roof. The flat roof of a poop cabin also serves as an observation platform called the poop deck. Officers and high-ranking sailors often used this area as an ideal position for observing the crew at work.
The poop cabin on a sailing ship generally served the same purpose as the raised bridge area does on a modern ship. The poop cabin could be used as an officer's mess hall during meals, as well as a storage area for maps, journals and official logs. The poop deck itself was a good vantage point from which to assess the condition of the ship's sails, since it was usually positioned behind the shorter third mast, or mizzenmast. If the captain was not at the helm himself, he could generally be found on the poop deck issuing orders to the helmsman.
As sails gave way to engines, the need for a functional poop deck decreased significantly. Almost all of the vital command orders could be issued from a centralized bridge which overlooked the entire ship. Modern sailing ships may still have an elevated cabin in the aft area, but the poop deck is little more than a raised platform suitable for sunbathing or other recreational uses.
Why Is It Called a Poop Deck?
While "poop" has a distinct connotation in English, a poop deck doesn't have anything to do with fecal matter. It's actually the product of a long game of inter-language telephone.
The English term "poop deck" is from the French "poupe," which means stern. The French term, in turn, comes from the Latin word "puppis," which also means stern. The origin of "puppis" isn't clear, but it was also used to denote a person's backside. So perhaps "poop deck" isn't so far off after all.
Where Is the Poop Deck on a Ship?
The poop deck is (ironically) at the very back of the ship. It's raised higher than any other deck and serves as a roof for the poop cabin. Again, the poop cabin isn't the bathroom -- that's at the very front of a ship.
What Kinds of Boats Have a Poop Deck?
Most sailing ships are designed with poop decks. Even modern sailing versions tend to have them, though larger commercial ships don't.
Cutter
Cutters were designed for speed and were used as warships in the 18th century. Modern cutters are still used today by government agencies such as the Coast Guard.
This type of ship has only one mast and typically has square sails. While optimized for sailing, it can also be propelled by oars.
Brig
When most people think of the traditional sailing vessel, they probably imagine a brig. This type of ship has two masts and is quite large. Due to its size, it was a common sight among the various militaries and merchant fleets. Brigs have several square sails as well as fore and aft sails.
Clipper
Clipper ships came into fashion in the 19th century. Though larger than cutters, clippers were smaller than other shipping vessels and designed for speed over carrying capacity. Their large sail area helped them catch the wind, though the exact number of sails varied by ship.
Schooner
While brigs were designed for trans-Atlantic travel, schooners were built to navigate coastlines. Their many fore and aft sails allow them to agilely move around rocky coasts that would prove dangerous to larger, bulkier vessels. During the 18th century, they were popular for fishing and coastal trade.
Carrack
Carracks dominated the seas in the 14th to 17th centuries. These ships were enormous and sometimes had four masts. Used for exploration and cargo, these ships helped expand the known world for Europeans.
What Was the Purpose of a Poop Deck?
If the poop deck isn't for pooping, then what was it used for? As it turns out, its high elevation was designed for three purposes:
Navigation
Before the modern-day, sailors had to navigate by the celestial bodies and landmarks. A high point, such as the crow's nest, gave sailors a better view of the surrounding ocean. However, reaching the crow's nest was arduous, and the space itself was cramped. In contrast, the poop deck was relatively spacious and flat, allowing officers to stand comfortably while getting a good look at the sky and sea.
Observation
Ranking officers were like supervisors over ordinary sailors, as they gave orders and made sure they were being followed. The poop deck was ideally situated to observe sailors as they worked. If officers didn't like how a job was being done, they could intervene immediately. Additionally, sailors were less likely to slack off since they knew they were being watched.
Protection From Waves
When sailing ships were the predominant vessels on the sea, even the largest were much smaller than today's giant cruise and shipping boats. Since they were smaller, they were at a bigger risk of capsizing when storms hit. Waves can easily reach 30-feet tall during a storm, putting even the mightiest ships of the day in danger. The poop deck created a kind of buttress that protected the ship from waves coming over the aft.
Why Don't Modern Boats Have a Poop Deck?
Modern ships are large enough that they don't need a buttressed aft to protect them from high waves. Now, captains generally command from the bridge, which is enclosed.
So, when did shipbuilders stop including a poop deck? The last ship to have one was the RMS Titanic. The boat that famously sunk had a poop deck that measured 128 feet long and was reportedly the last refuge of about 1,100 passengers who fled there as the Titanic started to list. It's important to note that the Titanic's untimely demise had nothing to do with the decision to do away with poop decks -- the construction of ships without one was already in motion.
