They may put you to the back of the line if the ferry is crowded, and it's expensive WITHOUT a towed vehicle $25 last time I took it.
It's pretty but a boring after the first 15 minutes.
Last but not least they're doing the "terrorist search" on vehicles. You've got to be there very early and if they decide to search your whole Airstream, you could have to wait for the next ferry. I haven't traveled that way much, but I did go through NYC one time by mistake WITH the Airstream. New Yorkers are nice... they all wave but for some reason they only put up one finger.
OMG! TAKE the GARDEN STATE Parkway!
On my way back I actually went through western NY, across PA to the west of Philly and then cut back over. All in all, a much less nail biting trip.
Paula