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Get one of these and mount on the transom. https://www.basspro.com/shop/en/transducer-mounting-plate Trim it to fit around that area. Then you can try that location and if you get turbulence, you will be able to move it and won't have to worry about holes in the transom. I went ahead and screwed the plate in mine but you can use adhesive to stick it to the transom so you don't have to put holes in.