Not sure how I should go about tracing this image

http://imgur.com/tSx39nq

http://imgur.com/oAQz4MO

I'd like to be able to have the option of adding colour when finished. I have done some of it so far but I stopped at the fin as shown in images. should I pretend the fin isn't there and go back and do it as a separate object or what? Sorry for noob question