Sure you can build your own, but this one is so much nicer.
I was a bit concerned because when I bought it, it had only one review with no written comments.  Sure it was a five star review, but who knows these days.<br /><br />In any event, I can report that this product deserves the five stars.  It looks nice, and much better than what I was planning on making with either a wood dowel or some PVC pipe and fittings.  I ended up getting a second, so I have a flag on my stern and on my bow.
Rating: 5 stars