Mad about Science: Water in the age of sail

By Brenden Bobby
Reader Columnist

Disney’s Pirates of the Caribbean franchise has solidified an image of the Golden Age of Piracy in the public’s eye: swashbuckling pirates fighting for plunder amid feats of derring-do while living a freebooter’s life of adventure and fun on the high seas. Reality was not very accurately reflected in these movies — and for good reason. You wouldn’t want to watch a historically accurate movie about pirates for a lot of reasons that we’re going to explore here.

Despite being made entirely out of water, the oceans are the largest deserts on the planet. Saltwater has about 3.5% salt content, which is enough to poison you if ingested. This high salt content requires more water for your body to flush it out, exacerbating dehydration and causing a slate of nightmarish side effects ranging from nausea and vomiting to hallucinations, seizures, and even falling into a coma and dying.

This means that, despite being surrounded by water, pirates weren’t able to just throw a bucket over the railing and replenish their stock. They had to source freshwater from somewhere else.

Water and provisions could be found at ports, but getting them was difficult when you were part of a known pirate crew. Outposts occupied by the Royal Navy were hostile to crews of thieving looters, so simply sailing to any open port to hawk booty and sling water wasn’t an option. This reduction in reliable supply increased the demand for fresh water and thus inflated its value in ports willing to trade with pirates.

A chest full of loot was all well and good, but it didn’t grant any benefit if you died of thirst hoarding it. It wasn’t uncommon for plunder to be traded for drinking water, as survival was more important than wealth.

Each pirate would need about a gallon of water per day to stay healthy. The largest pirate crews numbered at least 200, which seriously reduced the amount of space for plunder when factoring in how much water would be needed for monthslong voyages.

It was common for pirates to target merchant vessels not only for their wares, but for their water as well, effectively dooming merchants far out at sea. Blackbeard was infamous for plundering water to quench his crews and doom his victims.

Another method for acquiring water in a desperate situation was to rely on the sky. Tropical storms would whip a pirate crew into a frenzy as they would use every possible surface to collect fresh water. This came with a condition, of course — crews would need to wait several minutes into the storm for the water to wash away the immense amount of bird feces covering every surface of the ship. No one wanted guano-flavored water.

Every available resource was diverted into collecting water during storms. It’s likely this was done on virtually every seafaring vessel and not just pirate ships. The sails would be manipulated into water channels to fill barrels while crewmembers would ferry empty and full barrels into positions above and below deck. This was hard work when you consider that one gallon of water weighs 8.34 pounds. Ships had containers of different sizes for storing and transporting liquids, including water. These were: barrels at 31.5 gallons, or 262.71 pounds; hogsheads at 63 gallons, or 525.42 pounds; butts at 126 gallons, or 1,050.84 pounds; and leaguers, at 190-200 gallons or 1,584.6-1,668 pounds.

This didn’t account for flasks, bladders, canteens or the open mouths of the crew that they likely filled as much as they could during the storm.

Everyone thinks of pirates as always being at sea aboard their ships, but this often wasn’t the case. Crews had maps and charts to lead them toward springs, and these were coveted more than any treasure. They also applied forms of the scientific method once they landed by identifying specific kinds of plants that would grow near sources of fresh water, such as ferns and morning glory vines, while avoiding plants they learned grew in dry and sandy conditions. Pirates would also track the movements of birds and follow them to sources of fresh water.

As anyone with a water bottle knows, you can’t just keep refilling it without cleaning it out before it begins to get a funny taste. Black mold and algae begin growing inside modern metal water bottles, so how did pirates store water in wooden barrels for a month at a time without a way to clean them?

“Live water,” as it was known, was a serious issue for seafarers. Things grew in water such as mosquito larvae. Drinking live water has been described in pirate captain logs, and it was said that you could feel everything wriggling about the whole way down. Gross.

A method for counteracting bacterial growth was to char the inside of the barrels, which is still used in alcohol production for whisky and bourbon. This created a form of active charcoal filter like the ones used in fish aquariums. Pirates would also drop silver coins into barrels, as they were believed to have mystical healing properties. As we’ve seen with colloidal silver supplements, they were onto something, as silver has antimicrobial properties.

Heave ho and stay curious, 7B. Arrr!