I am trying to make a new design for a water canteen on CATIA. I'm trying to rotate the orange line in the figure around the two circles at each end to form the outer surface of the bottle. I'm not sure which tool to use and how to do this.
Hmm I'm not entirely sure as I've never used Catia / BIM but in most CAD software there's various functions for things like this.
Revolve comes to mind which a quick search shows me Catia does have. You'd basically create a polyline from the center of one end to the center of the other and then use it as an axis to revolve around.
Other terms I can think of are Extrude Along Path or Sweep. I found this guide which may help you more - it looks like Blend may be an option as well.