No, because the hiatal hernia is where the esophagus goes through the diaphragm, you wouldn't be able to push deep enough to feel that and you can't see them at all externally. And, although the band itself looks quite prominent on an x-ray, it's partially obscured by your liver typically, so you should not be able to feel it externally either.
An x-ray is not the nest way to show an incisional hernia, since they are composed entirely of soft tissue. You might need an MRI or CT scan.
The other thing you could have would be a diastasis recti, which they always say usually occurs in babies or pregnant women, but my dad has one so they sure aren't limited to those populations.
http://www.nlm.nih.gov/medlineplus/ency/article/001602.htm
Although they describe it as a "ridge", my dad's just looks like a big bulge slightly below the breast bone and it worsens with "sit-up" like motions. It looks like the alien is about to pop out of his chest when it happens.