I just thought of one while perusing this thread. Next time someone needs me to step in, let me know.
Go for it Mobius. I just got home and have to head right back out for a meeting. Good one Red. I really didn't have a lot of faith in my answer. I never did find a picture like you had. I even Googled "fence hammer" and such and never got anything. I just took a wild guess.
Ahh the city boy reference was a reason it was a challenge for me, not a reason I should get it. I don't build literal or metaphorical fences.
I already forgot what I had in mind. Regardless, here's one I came up with. Basically if you've ever used one, you'll know immediately, if you haven't, it should be pretty tough.
its definitely a foil, could be used for water or air or any fluid something, i will go with water. you bolt it to a boat and it smooths the ride.