Goya and Shioi really aren't but fanartists have a habit of making them sortie without machinery for who knows what reason.
The reasons aren't hard to imagine. Goya doesn't have rigging so much as a thing she's sitting on. Shioi has some stuff referencing her ship, but it isn't clear what it does or how one would use it while trying to swim around underwater.
Those tits are not "large" by anyone's standards, especially not in a universe where Atago and Iowa exist.
fanartist seem fond of making her that big though she's remarkedly moderate, especially by the artist's standards (same guy made Amagi and Unryuu, easily among KC's bustiest looking)