My ferries don't work

[zombones 0]

I have one land with developed RCI, and another island with nothing.

Then, I zone for only commercial on the undeveloped island, and it develops (mostly growable mods from simtropolis and other sites), but no one is using the ferries i built for sims to move from one island to the other.

Why is that?

[SC4BOY 20]

They will fill the jobs closest to their homes first (including links to other cities) then will travel the distance. Or if the "travel time" is too long, they also won't go there. And of course you may have a problem with the stations.. no road link, no power, water too shallow,  etc

[zombones 0]

Nah, i zoned on the empty land with no connection at all to the developed island, and the commercial lots still grew ( I only zoned commercial lots on the empty island). The stations themselves are fine and linked up to the road.

[jim 546 43]

Put some Res. and Ind. into the commercial city as well, this seems to encourage neighbour connections.