If it's 2.1 kts, can you point into it in the fairway, power slowly forward, and hold the boat in position? If so, you could effectively (maybe), back into the slip while still in forward, reducing throttle a bit. I'm thinking that you never use reverse in this approach. You'd need to be careful to never loose the bow, you'd have to keep working the rudder so that the stern stays directly behind the bow, and into the current....even if you're not initially aligned with the slip. If you loose the bow, you'll surely end up pinned against the pilings as indicated.
I hope you have good rub rails, that will help if you end up against a piling. If the rub rails touch either piling on the way in, you'd still have some control of the stern, again in forward all the time.
It's a tough one! I knew a guy who got good at this in Newburyport...he practiced the drill near some moorings before trying it in the slipway. Master this and you'll be one good close quarters boat handler!
The technique you are describing is called ferry gliding by some.
Thanks for the encouragement that it might be possible in this situation.
I tried if for about half an hour and it was very tricky.
The boat was slipping port even while going straight back.
The rudder was very reactive.
A couple of times I got close but the center of my stern was lined up with the pole so I had to bail.
Starting in exactly the right place escaped me for about 6 tries until someone showed up on the dock and we just fought it in and suffered the scrapes.
Sadly their is no rub rail at all. The hull bulges out below the rail.
I was thinking of a fender board but the chanses of it getting pulled out of place are almost 100%.
I also thought about laying against the pole on purpose, fendering it properly and bending the boat around the pole but then I can't figure on how to get to the dock with a line.
My neighbor is a very short power boat that doesn't reach to pole.