The only way to know for sure is to have a section cut out say a 4 x 8 inch to see how deep it goes down .
A concrete patch can repair that part.
Since it is side to side it does appear that the weight of the deep end and or the ground underneath settled during the winter.
Over all it does not look fatal, but if you plaster on top and it settles any more you will have a crack in your plaster.
To the above posts - how is the structure of the rebar, thickness of the gunite and what kind of base was under the gunite if any.
Also do you have water under the pour. My pool actually has a natural water running under it - its just how the site was....
In New England or CT we over engineer our pools with rebar and spray 12" thick gunite all the way around. Many builder use thinner or 8" gunite and
then will make a T or a cap on the walls at 12" for coping. We spend an extra 2- $2,500K on base gravel, steel and gunite, but even my pool has a small
hairline crack.
I can't fault your pool builder, but it should be checked out before you spend a lot of money on the finish.