Justification: As it stands, there's extremely little benefit to Skill Focus: Sail at 12. Most swash builds do not go deep enough to pick up the EskF: Sail option, and so it just ends up sitting as +5 to a skill that Swash doesn't have an easy time fitting into its core builds given the large number of skills it needs to take (craft mastery, discipline, lore, a social skill, parry, spellcraft, and tumble). If opened to a generic skill focus/epic skill focus, it would usually free up a single epic feat for 21+ swash builds (who would usually take skf: discipline and forego taking eskf: disc).
It would also open up options like 21 swash / 4 lm / 5 wm as a variant of the popular 21 fighter/4 lm / 5 wm (with a slightly stronger offense though less durable due to the lack of DI available to heavy armor users).
Thematically, Sail doesn't obviously fit in with the class fantasy of Swashbuckler. From the description on Arelith's Wiki:
The class is pitched as a duelist, not as a sailor. It has no synergy with Sail, so these feats just end up being kind of useless and random additions.The swashbuckler is the paragon of panache. Equally formidable in both dueling and discourse, they exude daring and bravado. Unlike the unruly barbarian or uncultured druid, the swashbuckler wins fights using their brain and their finesse rather than brute strength or magical prowess. Foregoing heavy armor and bulky weapons in favor of acrobatics and precision, the swashbuckler is a force to be reckoned with.
