I have a delivery on the other side of the river in Cincinnati, about 6 miles, as the crow flies, trouble is, I have to go in a loop around 275, and come back around because of the river and bridge placement, about 32 miles! The ferry will make it 8 miles.

Never been on the ferry, my husband has, and thinks it could work, but I am nervous. I will take a test run, if there are enough people to say I should try it out.

Ok, cant comment much on cakes but can comment on ferries. First thing I'd say is call the ferry company and see what kind of access it is onto the ferry, I'm in the UK so I know there will be a world of difference with ferries over there design wise but I recently drove over to the Isle of Wight for the festival which is about a 40 min ferry ride across the sea. The ferry journey was smooth as anything and even the waves were very fluid in movement (no pun intended) so my GUESS is that it would be fine because there are no sharp jolts even if its a little choppy. The only issue with me and my camping gear was that driving onto the ferry, the section for cars was hinged at the middle so whichever section could be lowered so you could drive on/drive off which makes for a very steep slope driving onto the back, one my Betty (18yr old peugout 106) couldn't handle and despite my protests of "like hell am I taking my foot off the brake till this thing is raised level again" there may or may not have been a slight incident where my foot left the brake and even with the handbrake pulled almost under my chin, the car rolled back and almost hit the car parked behind. I'm guessing this kind of thing might cause cake issues...

Good luck! =]

Yeah, that sounds like it could be a problem with a cake, lol. Our ferry is pretty small, and I know you can just sit in your car, or get out and walk over to a rail. I think it is pretty flat, though.... Maybe I will take a test run, just for fun. With the kids on summer break, we are bored everyday, I could take them and they would be thrilled. Get an ice cream, and it will be a life long memory, lol,

We have a lot of little islands around, and I deliver on ferries all the time. I've never had one that was rough enough to actually damage the cake.

Most of ours are all flat, they just look like barges, but there is one that I have ended up parking on a slant on each time.

I take a level, a big piece of plywood, and a bunch of towels, lol. I always drag my husband along, so he can hold onto the box as we drive on, then just shove towels under part of the board til it's level for the ride.

That's the only time I put the cake in the backseat, as I find it's easier to get it sitting level.

The only time I was on a ferry when it wasn't a smooth ride, a hurricane was coming that night. But I'm sure it varies.  You might want to consider how to handle the issue of whether would get hot in the car during the ride since you have to turn off your engine. Down here it can get pretty hot, pretty fast.

Well, I finally got a chance to take the ferry today, after dropping off my kid's viola at the music shop, since he never practiced. I actually drove right past the place I have to drop the cake off at. It is literally right across the river from me, about a half a mile from the ferry on the Ohio side. I am 6 miles from the ferry, on the Kentucky side.

It was raining, and we have had TONS of rain the last 3 weeks, so the river is pretty high and muddy and fast right now. The ferry ride was smooth as can be. I even left my engine on, in the air conditioning. The concern is the hills on both sides of the river! STEEP roads that double back and zig zag, cut into the side of STEEP hills. We are talking 3rd gear, I could hear my engine straining, and I normally can't hear it at all. That was coming up the hill, toward my house, so I will have to brake the whole way going toward the river, no gas at all, for about a mile. 

I think it is the perfect excuse to buy a cake safe. Because I am crazy, right?  I can get there 2 other ways, that go in the opposite direction. The map shows I can go 275 to 75, to river road, 24 miles, (to the right, in blue) Or to the left, 275 to 50 through Indiana, 28 miles(to the left, in blue)  The road in pink in across the ferry, 6 miles (it wasn't an option, I drew it in paint, lol) 

Also, even if I go the LONG way, I will have to go up a steep hill, you cannot get to the venue without going up their drive, with is crazy steep, so I cannot avoid the hills 100% anyway.