The attached page from Good Old Boat talks about ferry gliding.
It makes sense in open water but will the current really run consistently in among the finger piers?
You can't read the text in the attached page but the picture sort of explains it.
The concept is that if you are in strong current you just put your nose toward the current and adjust your power until you have a sog of 0.
Now you can move sideways, forward or back just by minor adjustments of throttle or helm.
So even with strong current you can move very slowly in perfect control into a slip.
This must be an open water situation where the docks are purely surface setup and the current flows freely. In LIS where I sail I'm pretty sure the current flow every which way depending on what the shore line is doing.