open space between surface and arcs

 From:  Glenn Claes (GLENN)
6668.1 
Hi All, I'm Glenn.

I'm new to Moi and new to nurbs modeling.
I finally found some time to start to get to know Moi a bit.
The tutorials and the forum already helped me with some of the basics, so we are getting there step by step.
I guess that working out the correct strategy to model is the most difficult part.
So be sure to hear from me again on this forum,because I will definitely need some tips in the near future! :)
By the way, most guys on this forum and tutorials make it all look to easy!!! respect for you guys! ;)

So to get down to my topic/

Today I noticed that when I zoom in on my model, that there are spaces between the arcs I drew and the actual curved surface.
When I draw an arc in Sketchup for instance, I know that I can increase the number of segments to get more accurate and smooth result.
Since I'm new to this nurb modeling, I'm not sure if that is also the case here?
I think it's not.
Also the actual arc that I drew doesn't show the same segmentation, and there are no options to specify the amount of segments..
I must say that the segmentation is only visible in close up, its not visible when i look at the entire model.

So my real question is..
Am I just looking to close at my model and there is nothing wrong?
Or did I do something wrong in the process (change a setting?) and my model is in fact not detailed enough to give a smooth surface.

I'm asking because eventually I hoping to export and CNC carve and/or 3D print some of the models I make.
So I would like know if I'm doing anything wrong from the start.