What Is Mariner's Soap, or Sailor's Soap?

A character in one of Karen Blixen’s stories, “The Deluge at Norderney”, once said,

“I know of a cure for everything. Saltwater. . . in one way or the other. Sweat, or tears, or the salt sea.”

As I mentioned in previous articles, my family loves anything that involves the sea. Saltwater runs in our blood. So we created a soap specifically for those who enjoy “The Salt Life” and called it Surf-N-Suds (SnS). SnS is our Adventure/Go-Anywhere Soap. (See description below to learn more about Surf-N-Suds) The rest of the world would commonly refer to our soap as Mariner’s Soap or Sailors Soap. So what is it?


Put plainly, it is a soap formulated to lather up in saltwater. This is something normal hard bar soaps don’t do very well.


Typical hard bar soaps use caustic soda lye or sodium hydroxide to react with oils or fats to make soap. The resulting sodium compounds that make make up the soap dissolve easily in freshwater and help remove the dirt and the excess lipids that make your skin feel dirty and greasy. However, in saltwater, the sodium compounds don’t dissolve and create a lather as easily as they do in freshwater. This is actually because of the high magnesium levels in seawater, but that’s a chemistry lesson for a different day.


The easiest option would be to use a potassium based lye called potash or potassium hydroxide. The magnesium ions in the seawater have a different effect on the potassium compounds that remove the excess lipids and clean your skin. Potassium based salts are what you use in your liquid hand soaps. However, therein lies the problem. Potassium based lye only creates liquid soaps and liquids require a container of some sort - usually a plastic container.


Plastic containers are a problem worldwide, but they especially present problems for anyone living at sea. Every bit of trash brought onboard needs to kept onboard until you can find a proper trash receptacle. And if you are visiting an island, your trash now becomes their problem. The result is trash mountains in the middle of paradise. Don’t believe me? Visit the Cayman Islands and ask what the islanders think of their trash mountain.


So what’s the big deal? Hard bars lather fine in freshwater, so why not just shower with freshwater. Well, if you have the money for a water maker and the maintenance involved, it’s not a big deal. However, if you’re living on a sailboat, expenses add up quick. Freshwater becomes more precious and you need to find ways to conserve your precious resources.


There is a solution that doesn’t involve plastic containers and helps those living at sea conserve precious resources. Coconut oil. Coconut oil when saponified with sodium hydroxide still creates a hard bar but also dissolves easily in seawater. Our SnS bars are made mostly of coconut oil. So, they don’t have a problem creating a good lather in seawater.


Now some may argue that coconut oil soaps are really drying on their skin. Normally that is true, but we solved that issue as well with specific superfatting and sugar. Wait! What?!? Fat and sugar?!? No worries my friends. I’ll explain more about superfatting and complex carbon chains of sugar in my next article.