You sort of answered your own question, in my opinion. I carry a Mini Boat Paddle from Quaker Boy. Small, compact, doesn't sound great up close but has that high pitch that not only carries a long distance, but also cuts the wind quite well.
I believe they're technically out of production, but if you visit their website they can still be ordered as "an old favorite," or catch one on eBay. Cost should be in the $15-20 range.