Sailing speed increases in Hostile and Lawless Waters. In Lawless Waters, Acceleration also increases.
This can be added as an Optional Skill on the
Fancy and
Charles II ships using a Design Blueprint of the Order FS part (itself crafted through transmutation alchemy using a Broken Order of Merit accessory as a base item -- but only if you can defeat the Deep-sea Divers or Aide Squad super-bosses in Rome and purchase the Broken item for 5k Roman Coins).
Note: I'll try to update this comment when the Order items are added to the Database. Thanks for your patience.