Modeling Helmet ?

 From:  Anis
3623.9 In reply to 3623.8 
Hi Michael....

>>>so think of your base shape following more like the blue ink here:
>>>Then later to make that ridge line you will cut something like this area out and put in some new surfaces in there
I am not thinking about this idea before, good idea..., I have to try...

Here is result from make larger curve then use blend.
But yes, the pole area is not smooth. Open the 3dm file.