The language of sailing ~ by Richard Mayne
The language of sailing - Google Book Search
Often, terms like these owe their usage to Greek or Latin words.
ie: The Latin "porta" means opening, gate, & etc. This leads to such English
words as "portal" (entrance), and hence to porthole, portlight, and computer port, etc.
And as George Carlin asked: "Shouldn't a hernia be called a hisnia?"