I have asked this question before but I didn't get a helpful answer.
How do I sink a flume into a body of water (without using something like the Poseidon PeP)? It should look something like this:

Thanks for helping out.

It all depends on what game you're doing this in, I don't think you can properly do it in RCT1 or 2 without mods, and for RCT3 it's best to get a CTR.