When I skip under docks with spinning, I rarely have a fish wrap me up. I tend to keep more tension on the line because the fish will nearly always hit the bait as it intially falls. I immediately set the hook at the first twitch , and pull back hard while reeling fast. I also have a couple spinning reels that have a fairly high gear ratio so that helps too.
My home lake docks dont have a lot of obstructions under them though.