The Type XVII is a German coastal submarine. Its high-test peroxide propulsion system combined air-independent propulsion with high speeds. However, HTP is expensive, which hindered the production of the Type XVII. Post-war, most were scuttled or sold, some reaching Oceanyka, where it gained a niche for defending coastal waters or facilities from amphibious invasion.
As a coastal submarine, the Type XVII is specialised at defending key locations with great stealth and disproportionate firepower.