How to put boats on a lake?

@thevogel My plan was to use the store item that lets you charge a fee for sims to go through it on the entry way to a boat house, then have the deck come off that building. The problem I'm having is that the mooring cleats will not place on the dock and I don't know what exactly it is I'm doing wrong.
When I try to place either the mooring cleat or mooring post it says It can only be placed in the ocean.
https://puu.sh/AvEvY/78a16c17a1.jpg
Here is a screeny of the area I'm working with at the moment.

I'll be pasting this response into both threads I've made on he subject, but I did eventually find the solution to this problem.

Lots that start as flat ground with a lake made via the water tool in terrain tools will not work for this purpose. The community lot needs to be over "world water", that was created before the lot was placed.