Shipyard access blocked

Describe the issue
The shipyard appears as "blocked", but is not really blocked

Expected behavior
The "ship access is blocked" shouldn't be displayed, or cargo depot should not be placeable

To Reproduce
Steps to reproduce the behavior:

1. Load attached save 'Shipyard_issue'
2. Delete the Cargo depot to make the message disappear, place it to make it appear

Additional context

• Game version: 0.4.5b

Attachments
Video about the issue
Shipyard_issue.save

Files not imported: Shipyard_issue.save

If the area in the water is not deep enough, this will happen due to the placement of anything like Rocks or Dirt to create the area for the Cargo dock. Shallow oceans bad.

I have never been able to get the button that fixes this to work, as shown in the video.

This bug is about the fact that we allowed the player to build the cargo dock despite the fact that it ends up blocking the shipyard. We need to take a look on how hard it would be to figure this out upfront.