I am little curious if there is any possibility to make floating train/caravan with ~3 houseboats. Theoretically this is possible in TS3 without any mods- you need to buy 3 houseboats, park them closely together and then order captains to sail into the same spot, but you need to have luck that they will choose the same path, same speed and no crash to desktop. I am sad that Maxis didn't allow us to make longer boats, so they could look like real big ships, so I am looking for alternatives.

Don't get me wrong- I am not looking for someone who will do it for me, but rather how I can start making this mod and if modding tools even allow for this.

I haven't looked, but imagine you can make a houseboat larger, by cloning with TSRW, or maybe s3oc. Next comes the routing issues.

I think the only way this might be possible is you would have to edit the world in CAW to make the routing in the water a direct path. Since I have delved into altering worlds. Most of the water is routable so I don't think they have a "Path" to follow which is why you can click to swim here, boat here and so on. So with that you would have to make the rest of the water unroutable. Now where this would make routing issues is if all boats, sims, water taxis and so on can only be in that routable water. So any sim performing these actions would be in that routing path. You could make it wide enough to fit houseboats and other things so maybe it wouldn't cause routing issues but with this game you never know.

It would have been cool if you could set routing by vehicle type and draw direct paths by type but alas we do not have that capability with Boats and watercraft in the game. So as long as its routable you never know what will pop up.