My parents had a new dock built at their lake house. The dock sways a bit when you walk on the second level deck that is over the boat. The dock has a lot of pilons of what a I think is 8x8 PT. The decking is using trex and they didn't level all of the joists so it looks uneven at some parts with a noticible lump on one section. I don't think they used joist hangers and it looks like the fastened the joists to the frame with spikes.