If I understand your dilemma, the device is restricted as to height due to the length of its "pole" that extends down into the Scotty rod mount. You are also restricted due to the thickness of the rounded gunnel on your boat.
If that is correct....Just about the only solution that comes to mind would be to find a piece of aluminum square tube that is the same thickness as the gunnel...PLUS the thickness of the base of the Scotty mount. You might have to shim the square tube to make it all fit.
Say your gunnel is 1 1/2 inches from the boat's side to the edge of the gunnel, and the base of the Scotty mount is 2 inches. Your square tube, along with any shims needed, would have to be 3 1/2 inches square.
You'd mount the square tube right under the gunnel using long bolts and backing plate(s) on the outside of the boat. i.e. the bolts would have to be 4 inches or so long.
Now....the major "solution" is to turn the Scotty mount upright. That will give you another inch or so of height that mounting it sideways did not. Stick the "pole" of the anchor device into the Scotty mount and everything should fit fine.
The biggest problem that I see with the above solution is that there will be a lot of pressure put onto the square of aluminum and its mounting bolts. That amount of pressure will be determined by the weight of the anchor that you put on. A lot of leverage will be placed on the Scotty mount, too.
May I suggest another answer....
Just mount one of these on the top side of the gunnel and be done with it. It will help you raise your anchor but won't need all of the engineering to mount it. There may be some reason why you require the extended anchor device...but...if not..maybe a simple anchor chock will do the job. regards, richg99
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