You can fabricate one. My neighbor did and I will send you some pics in a week or so when I get some. Also I just made a set for a friend. There was a skylon mount on here ini the classified ads and I just bloted some cans to the mount and that was that. Try contacting skylon becasue they made the bracket that I bought off the guy on WW
you can find everything you need at home depot. I used 1 7/8 inch galvinzed pipe paintied black and some large u-bolts painted black. I clamped the cans to the pipe. I had to use a rubber pipe connector (3 inch) to stop the u-bolt from sliding down the pole in rough water
i mades some cans out of a 6" pvc coupler then i bought some 8' L brackets , i mounted a L bracket on each side of the pylon ,i drilled a hole threw the pylon then i mounted the speakers on the bracket
I've got a set of quick disconnect wake tubbies (6-1/2") with the bracket for a extended pole I no longer use. Here is a pic of the pole & bracket, if you're interested I can get a pic of the speakers this weekend.