Howdy and happy new year to you and yours. The trails vary. Some disappear quickly and others last much longer. I've seen them spraying black trails over here and also seen thick black trails from inside a plane being sprayed by another plane that passed by. They do also spray over the sea. This can be seen on some weather charts. They spray wherever is needed to achieve the desired weather change. It's shocking that they do this over our heads whilst saying it's not happening. Here's an example of just one of the weather modification patents. Check out the nasty contents https://www.geoengineeringwatch.org/patents/patent-3613992.pdf