How is the exterior?
You don't want to treat the symptoms (the crack) and ignore the disease (water)
That's a good point, but usually vertical cracks are not worrisome in themselves, as they commonly happen as the concrete ages, even if the foundation is good.
"Why is the water so high outside the wall?" Is a good question to ask. We have a similar vertical crack in our basement wall, and I thought water was coming in through it during heavy rain. It turned out to be merely a mis-adjusted sump pump (the water was allowed to accumulate too deep before the pump would turn on). Since I fixed that issue, we haven't seen a drop of water in the basement