I just did this exact drill by myself in a 43 Powercat out of road town. Checked out of sopers into cruz bay, Kevin dropped family off at Crown bay dock. I picked them up at 3:30 and we motored back to St john and spent the night in Canneal bay (which I would go further down st john due to the ferry waves ) I did this at thanksgiving so they days were longer. Crown is nice since you avoid all the ferry hassle. If you are late there are mooring balls across from Crown bay on that Island ( don't remember the name ) or you can stay in crown bay marina but pricey.

I did the reverse when they went home but had a little more daylight.

You will burn more fuel and if it is rough you will take a beating but in a power cat you can make time easy.

My next try will most like be redhook pickup....to avid ferry. next would be Cruz bay. next will be west end ( avoids customs..

As others have said have you forms ready to fill out and know the drill. It was my first time and a good learning experience.