When both mods are used, the buoys and ports from the Cargo Ships mod cannot be placed on water. Sounds strange, but I confirmed that removing just this mod fixes the issue.

When you look at the tooltip for the buoys/ports, do you see "Calibration" listed as one of the mods for those entities?

Hey, thanks for pointing this out. The algorithm involved was very old, from when I first started modding. I've now made it much more flexible. This problem will be resolved in the version I will release in a few moments.