Silence

Silence, whose actual name is Silas, was an artificer who worked for the Koan Empire. He partially developed an invention called a Dive Gear, a fixture that would allow any ship to briefly submerge beneath the waves like a koan submarine. After realizing the damage such a device could cause in the empire's hands, he defected and left his prototype notes in the care of his son.
Silence joined Jim Kestrel's crew and assisted as an artificer. A lifetime of working near cannons and machines had caused him to become deaf, which was what led to the misunderstanding about the pronunciation of his name. While Silence got along well with his crewm members, the only person he could directly speak with was the crew's Homyn Chef, Clara.
During Jim Kestrel's plot to capture Anh Edonia and sink a Koan Dreadnaught, Silence assisted the Scalfi in preparing his inventions. However, in his old age he did not survive the month spent in the elements hiding amidst the rubble.
Nevertheless, he helped in his own way by passing on his son's location to Jim and Anh. After a brief interlude sneaking into Balphuran, they were able to find Silence's son, acquire his notes, and finish building the Dive Gear. While he never lived to see a Koan dreadnaught sink, his work nevertheless helped make their victory a reality.