Wyrmsea

The inland sea known as the Wyrmsea was created during the magical cataclysm known as The Sundering, during year zero of the modern calendar. The magical explosion blasted much of the central continental landmass to shattered rubble, then hurled it high into the skies. The north-eastern edge of the continent crumbled, and the waters of the Lunar Sea rushed in.
The sea is largely circular, centred on the site of the ritual in the heart of the continent. It is deepest at the centre, apart from the island which forms the base of the floating mountains known as the Mountains of the Sky, held aloft by the magic from the ley-lines which powered the original ritual. An entire mountain was thrown aloft and crashed down next to Brankara to form the crater sea there.
The Wyrmsea gains its name from the wild dragons that roost in the Mountains of the Sky and hunt across the sea and the surrounding coastlines, making navigation perilous within the central sea. Only the sailors of the Wyrmsea Republic are brave - or foolhardy - enough to sail the Wyrmsea regularly.

Map of the Wyrmsea by Nathan Turner