Example: If your dinghy width is 60" then divide by 2 + 4" = 34". Swim platform is 32". By adding 2" to the platform this would make it equal to the dinghy width of 34" so then you would have chosen the 6" model.Hint: 4 inches of the deck mount must be used to secure to the platform.If your having problems determining the right mount, give us a hail at1.906. 553.6249
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