Mighty Servant 1

Drone ship OCISLY (Of course I still love you) being loaded onto transport ship MS1 (Mighty Servant 1) in the Bahamas

OCISLY (Of course I still love you) is a barge that SpaceX uses as a landing platform to recover boosters from their Falcon 9 rockets. 

The drone ship (essentially a barge) is floating in the center of the picture. The bow section of MS1 (Mighty Servant 1) is on the left and the stern portion is on the right. The body of the ship that joins these two sections has been submerged to allow the OCISLY to float right over it. When it is in position, the MS1 will pump the water out of the ballast tanks and the whole ship will rise until the deck is above the surface, lifting the barge with it. Then they will drive to Vandenberg AFB in California via the Panama Canal.

Via Silicon Greybeard, who has a post with the whole story.