Concept sketches for a tradeship of Avin (a warship would have a ram) and one of the water spirits employed to power it. Note that they are not to scale with each other. Many water spirits drive one ship. It also helps to imagine the water spirit being made of water, something that is not clear without coloring.

Here are some more notes on technology and spirits in the world of Righteous:

In the old days, hostile spirits roamed freely, but the legendary founder of Avin drove them out to the periphery. Spirits, like food and draft animals, are an essential part of modern civilization, with Avin on the forefront of their application to human service. They're used to keep fields healthy, to forge better metals, to move ships of war and trade and to inhabit material constructs shaped like animals, standing in for real animals (and needing no food or water).

Technology is a mixture of bronze age basics and "automation" and advances provided by conjured and bound spirits. Ships can travel without oars or sails, carts are pulled along by animals made of metal and stone and doors and gates can open on command.