Not near my boat for the winter, but it's not only the depth of the tracking fins, but also where your bunk contacts the hull, so how wide your bunks are set will change the depth/height needed for your bunks. Long story short, from the looks of your lift, I would probably raise the bunks as far as you can, might mean you need to get another section of dock, but that would be easier than the gel coat fix when a kid or yourself comes in too hot and smokes the driveshaft on the lift frame...

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