Can't put boat path under bridge in map editor

[purpleicecream]

Just what it says. Every time I try to put a boat path underneath a bridge I always get a "water required" message. Doesn't matter how high the bridge is. I've heard that boats will entirely ignore bridges during gameplay and go right through them without issue to reach their destination, so I'm wondering what the result would be if, while making a map, I simply put down a boat path first and then built a bridge over it. Can anyone confirm if this would work or not? Or can anyone tell me if I might be doing something wrong with my bridges that won't let me place a boat path underneath? Its not the terrain blocking me either, demolishing the bridge allows me to place the boat path just fine.

And if none of the above will work, can anyone suggest a good mod? I really would like my boats to go under my bridges. It seems silly that they can't.

[Metacritical]

boats included in Mass Transit take note of the height of bridges, boats that are not part of that DLC ignore the height of bridges.

[mbutton15]

It's just like putting rail/road over each other, you need to leave enough head room. So it probably is easier to put the boat path first and then just raise the bridge high enough so it goes over.

One thing to note when messing with water in particular is the game needs to be running, rather than be on pause, so it registers the affect of changes you make. I've certainly had times when I've being playing with shorelines on pause, try to place a quay against the new shore line, only for the 'shoreline required' message to appear. If I let the game run a short time I can then place the quay on my new shoreline.