if(!usr.client.screen.Find(/obj/HUD/Ships/Rark)&&!usr.client.screen.Find(/obj/HUD/Ships/Sloop)&&!usr.client.screen.Find(/obj/HUD/Ships/Schooner))
As you can see its practically the same thing each time, but I can't find a way of shortening the line.
~Ease~
That would probably be the simplest way to do it.
Or better yet, make a function that accepts two lists and searches for any instances of one list in the other, then you can use just that one function in every situation where you require this.