The 4 posts that you're talking about are probably the bottom pieces of the 4 supports to hold the main deck. There are supposed to be 4 starboard supports that slide into these 2 support the main hull. Supposedly, they are only important when the ama's are open. The boat must have drifted to the side a little when it was sliding off of the trailer and got caught on one of them. Note that you should have pvc guide pipes near the back of the trailer to keep it steady when loading or unloading. See photo below for the 4 supports, but it doesn't have the 2 pvc pipes mounted. They mount on the two horizontal square beams at the back of the trailer, and stick up around 6 feet or so. I put them on only when launching or retrieving the boat - they appear to make the boat and trailer illegal (too wide for highway use).
