In fact, there is no reason to suppose the SS Planter was not used for its intended purpose, as a coastal packet for cotton from 1860 & 1861.
Indeed, this photo from the period shows it used in exactly that way.
SS Planter proves that Southerners in general, and South Carolinians specifically were fully capable of building, owning and operating ships, and so puts the lie to various claims that, somehow, New Yorkers had an iron grip on Southern exports.