Got under my boat last week. Had been hearing a loud smacking noise when loading boat on trailer the last 2 trips out. Noticed the 2 outside trailer bunks have a gap between the boats hull and bunks. I can actually fit my fingers and hand between the bunks and boat hull. Boat only touches at each end of 2x4s where braces are attached to frame. Looks like 2x4s weren't crowned the right direction so the u,ed place in boards is facing up instead of down, or trailer braces are not right.
I've also heard of some other benchmark trailer bunk boards breaking on outside 2 bunks. Benchmark uses 2x4s Instead of 2x6s.