Watchtower Port has no specialty products, no particular pearls or gemstones, not even food supplies; it's good enough that they don't need to transport food from outside.
Occasionally, some weapons and equipment made by Dwarves would flow out from the Lost Plateau, and near Watchtower Port, there is an Elf City, so from time to time Elven weapons, equipment, and handicrafts appear in the market, worth a trading ship to come and go between Watchtower Port and the Talia Alliance.
In such circumstances, the docks of Watchtower Port are not just filled with fishing boats but also frequently with trading ships, mainly because the geographic location of Watchtower Port is quite advantageous, with trading ships often docking here for supplies.