Steamwrencher: A steam mechanic, somewhere in status below an engineer. Maintains and repairs steam engines, either plying their trade at ports or being hired on to travel with a steamship (though usually those latter positions go to engineers).
Engineer: A cut above a steamwrencher, an engineer is an expert in steam engines and may even design and build them. Often engineers are also inventors.
Weather mage: A weather mage is a mage dealing specifically with atmospheric, elemental and weather magic. Hired on ships to ensure safe voyages and deal with any bad weather or rough seas encountered. Also used in ship-to-ship battles.