I was referring to the built-in extension on the trailer. My extension is less than 4 feet, giving an additional 9 to 12 inches of depth. Given you need a minimum of 5+ feet of depth just to land the keel on the very back of the trailer, and twice that to land the keel in the middle, yes, I would still call it useless. On the other hand, if you had a 10-15 foot DYI extension you carry around, that can make a difference. DYI extension / tow strap is required to land the wing keel on the center board of the trailer given a normal boat ramp angle between 12% and 15%.
