I believe the openings for guns are often called "gun ports," rather than port holes, but the basic idea of a port being an opening in the side still holds.

And yes, I can tie a fisherman's bend, a sheet bend, a slipped sheet bend and, if I really apply myself, a short-end sheet bend (useful in mending things like a broken shoelace, but I generally prefer Bill's method, recommended elsewhere, for dealing with that issue - but's it a nice euphonious name).