How do I fix Google Timeline locations without deleting the entire day?

[Android Central Question]

I went on a cruise in the Caribbean last November. Most of the travel in the Timeline is surprisingly accurate, considering I had all mobile data and roaming shut down and was in airplane mode while in Honduras, Costa Rica and Mexico. BUT - time at sea seems to have seriously confused Google, which decided that I had spent that time in a port in Barcelona. I deleted the record of a day at sea, but that just put a strange supersonic flight from Cozumel to Barcelona in the night prior, added a trip between Barcelona and Nantes the next day before teleporting me back in time to meet my ship in the actual next port. I can't delete the false European locations. I've tried changing the times of that travel to a different day so I can delete that without killing the actual data about that morning, but that just spawns a copy and leaves the original trans-Atlantic fantasy trip where it is. I suspect the ship is being confused with home ports or something. Any ideas on how to get the wrong continent off my Timeline?