Sorry my friend, but this explanation for the origin of the famous "s" word is nothing but an "urban myth". Just have a look at any other language that is related to both German and English (being English the most recent language, and therefore not the originator of any word), and you'll see that they use almost the same word, with no apparent reason for that. And in no case can you make a connection between that stuff that sometimes hit the fan on high sea, and this word on the other hand. So it's clearly a fabrication!