It's funny that three people feel the urge to reply for the author and all of them are wrong :-)
Also I find it interesting that in Portuguese as well as in Spanish the word exists in both genders: el barco, la barca, o barco, a barca.
At least in Spanish, my rule of thumb is that "barco" is for bigger boats and "barca" is for smaller ones (and then you have Barça which is the football/soccer team).
Barça looks similar but is pronounced entirely differently (say “barsa”).
It is wrong but coincidently in a way that aligns with the sea-fairing theme