Can't Expand Ship Hull Beyond Bounds

Yep, u can however make a second ship. There's a big button with a + in it next to the 1 of ur ship in the top left, that lets u build a second ship, and u can make that ship the same size so u can have 2 large ships. That's the only way i know so far to keep building a bit larger. But i don't think u can make a third tho... But ya, that's it.