I was looking at the Google map picture of Haiti and the DR and I started panning around the Caribbean and thought I would try to find the Panama Canal. While looking at the amazing pictures of the canal, I noticed that in this picture it looks like a container ship has sunk right at the entrance of a lock. What am I seeing here?
I’m 99% sure that’s the stern of a ship that was at the edge of a photograph. The part of the image on the left is substantially darker than that on the right, which suggests that there are two photographs blended into each other along the line. Since the ship was “on the line”, this means that a photo with a ship in it was blended with another image (taken later) without a ship. Net result: picture of ship blended into picture of empty water.
Looks more like that ship just happened to be on the edge of one of the photos that was stitched to the next.
ETA: Damnit!
As already mentioned – definitely an artifact.
The “sinking” effect (looks like the ship is partly submerged) is probably due to a “mixing” near the edges of the comprising pictures – i.e., instead of just splicing the pictures, Google overlaps the pictures somewhat (over a few 10s or hundreds of feet), with the right being 100% RH picture, then gradually going to 50% RH pictue and 50% LH picture in the middle, and finally becoming 100% LH picture on the left. RH picture contained a ship; LH picture didn’t; result – the amazing gradually “disappearing” ship 
– which the eye takes to be a tilted, partially submerged, ship.
I live on a lake. Depending on the season, the water is either deep blue or coffee-and-cream brown.
For a few years, Google maps showed our lake as half and half with a nice sharp straight line separating the two colors. IOW, it was obviously an artifact of different images taken on different days, not a single picture of a real situation.
They’ve updated their imagery since, and it’s now several shades of brown with softer borders between the sections.
There’s a similar effect if one looks at a plane landing runway 18R at Amsterdam, Netherlands. The plane is missing one wing although the shadow is complete.