Those are reflections of lights inside the boat.We went at Lake Ness make a video of the Lake and later we sow those lights rotating in the sky.
That is the contrail of a plane, lit by the setting sun. It's far away, so looks like it is descending.Yesterday here in London that flames stay in the sky without fall.
It is pretty clear the second video was recorded from inside a glass enclosure. You can see the reflection of a table or something on the lower part of the image.We where outside the boat
Yep. I suspect it is your shirt, but maybe a table or something. It moves out of frame to the right as the camera moves.