Ok, again I'm assuming your not trolling...
The Flat Earth map you are referring to is known as the Gleason projection. It's one of many ways to show the surface of the Earth, but all of them have distortions. Why? Well...it's a 2d representation of a 3d object, that object being a globe. Several continents are stretched in ways that do not comport with reality. If you resize them to be geographically accurate, then the oceans get bigger.
The Bible, and please forgive me if you take offense to this if you are religious because I don't mean to be rude, but I don't care what it has to say about scientific concepts and cosmology. It's a bibliography of the people and tribes who participated in its writing. It's not a scientific source and shouldn't be viewed as such. It doesn't contradict science so long as you take things like the firmament as allegory. Objectively, we have never seen any evidence of a dome structure encompassing the Earth. There is certainly no physical evidence to suggest it's existence. If it was there, we'd know about it.