The Part of the boat where its wheel is located is called the Helm. It's the pivotal point where the most structural integrity is, thus making it the best place to mount a steering mechanism. Notably, a helm is often in front of the main cabin(s) (depending on the size of the ship) solely for traditional purposes. There is no mechanical necessity for it to be "elevated" above the main deck. Just throwing that out there. Technically, the wheel doesn't 'need' a helm, it just needs a structurally sound place to control the ship's rudder, but most commonly it's on an elevated platform... dubbed the helm.