Quite unfortunate that the sunrise was too cloudy in the far distance (only shades of blue, no reds).
Oh well. Still interesting to build a panorama of both sky and water. Sure it's only 4 images, but it sure was a beast to get correct.
Preprocessed (for color balance) in RawTherapee, stitched in OpenCV, cropped in Gimp.
As a note, you should check out the full size - 8624x4661. Top right image of the 4 was a bit out of focus (from not being able to use autofocus in the low light conditions), but everything else is pretty spot on.
Taken with Nikon D3200, 1/15s shutter, ISO 3200, 18mm, taken 4:41-4:43am on 2016-04-10.
GPS approximately 44.324041 N, 68.186324 W (Ocean Path in Acadia National Park).