In the far  South, on the west bank of the river Torr opposite the great Umbrella Trees, the Cave Fishers suspend their huts from the roofs of the giant caverns known as the Caves of Sevist.  
To catch the enormous Ribfish, the Cave Fishers rely on the tide, which in these parts, rises so high that it regularly closes over the tops of the Umbrella Trees, and ebbs so quickly that boatmen are often stranded in the treetops until the next high tide lifts them away.
The Fishers’ huts are each hung by one line that runs to the ceiling of the cavern, through a stout pulley, and down again to a brake-wheel mounted on the side of the hut.  The line passing through this brake, is governed by the fishermen, and is attached at its lowest extremity to a large baited hook.
As the tide rises, the huts, supported by bags of air, float up toward the roof of the cave - causing the hooks to sink down into the sea.  When the sea ceases to rise, the fishermen apply their brakes and settle down to await tide-fall. 
Thus, as the waters ebb, the huts are left swaying in the wind, high above the Torr estuary, while the hooks search down into the deep waters for the bite of a Ribfish.
Feeling the judder of his hut at the strike of a catch, a Fisher will release the brake and inevitably, the fish will be drawn to the surface by the weight of the descending hut. At low tide, riding the backs of the long-necked Queel or Sea-Dragons, the Traders arrive, moving from hut to hut to collect the Ribfish.  Then, as the Fishers rebait their hooks, the Traders, Ribfish in tow, depart for the markets.