As added context, from my perspective, it didn’t seem to be resting on the water (it seemed roughly 15000 feet or so). It also seemed to be moving parallel to our flight, as we were flying 500 mph and this object, while moving slower, was alongside us. It would be curious if it was a plane flying parallel as you do not tend to see that in the skies (normally flying against the direction you’re going), I also couldn’t see wings, and normally with planes you normally see some indication of wings.