Hisser

Found In the northern regions of the kingdom of Fathia is a unique set of river ships locally referred to as hissers. These ships are steered by oarsmen who slowly pole the ship along the frigid waters of the river Soshel. These boats only run in their winter and allow the northern trade routes to be maintained through the winter. Normally these routes cross the top of the continent in the ocean yet when winter sea ice blocks off the routes shift to the river. Starting at the city of Pirrala in the east and ending at the capital Zinedor in the west the Hissers brave the ice laden waters of the Soshel.
The Hissers are able to make this trip due to the reinforced steel guard that sits on the front of the ship serving as a blade with which to cut through any icebergs and protect the ship. This steel blade is also where the boats get their names from. The blade has been enchanted with a heat metal spell that allows it to melt and break a path forward if the ice fully covers the river. Usually not used to the full extent but left at a lower setting which causes the water to boil and steam right in front of the ship giving off a hissing sound as it gets poled along the river.
There are only 12 of these vessels as the skill set needed to navigate the river with speed while managing the enchanted blade at the bow is not one that comes around often. Each boat has a captain and two other crew members who are able to drive the boats. They as a group of sailors are referred to as the river drivers. A tight knit group of people who only bring new ones in when they lose a member of their group.
Prior to the rediscover of these blades out of the ice the trade had to be stopped in the winter or would be navigated to the south of the continent adding two months of travel to the voyage. When these blades were first found it was attached to a larger three masted sailing ship with markings from the Olic empire.