Cannot figure out how to merge ships

I am sure there will be a simple answer to my question but it eludes me, so forgive me in advance for asking. When I have ships at two different worlds and wish to move some from World A to World B how exactly do I do this? I have tried and tried just dragging and dropping and cannot get this to work. Someone please enlighten me! Thanks in advance as well.

you drag and drop fleets, not indivudual ships. if you drag a ship out of its fleet window, it will create a new fleet icon, and you can then move that.

Thank you very much for that. Also thanks for the game. I am enjoying it even with my arse being kicked on a regular basis.