I don't understand.
You go in bow first?
The current flows from your starboard side towards your port side?
The finger pier is on your port side?
Then you say that you make a starboard turn into your slip?
A STARBOARD turn?
This means that you are approaching your slip by going down current?
If that's the case no wonder you have problems. I can't conceive of docking in your slip by going downstream. You approach the slip going up current so you can use the current to slow your boat down as you make a port turn into your slip with just enough way on so she basically stops by the time she gets fully into the slip and nestles up to the port side dock.
Let me know if I've got it wrong.
Sail Fast Live Slow
40' Norman Cross trimaran