@valentynchikin wrote:
Thank you very much for your reply!
I have already studied above mentioned tutorial, but I could not implement the same technic in my case. In my example there are wave parts that are incomplete and surface could not be done. So either this technic could not be used or I just lack of skills ((
That technique can be used. It is a bit more involved, but it is possible.
However, This can also is done with T-Splines.

Let me know if the attached model with what you see in the image above helps.
The techniques @JHRendon linked to can also be very powerful. I'd use Blender as it is free, open-source software.