You forget that part of his "inexperience" was taking a rowboat across the North Atlantic - No doubt a foolhardy thing to many hereon.
Two men rowing across the N. Atlantic shows stones of remarkable size - and while he may have been inexperienced with a sail, he certainly was *not* inexperienced at sea.
I forgot nothing. Rowing with a partner is quite a bit different than sailing a ship alone. Especially when one has never done it before. The point is that Abby isn't necessarily competent. Blyth did it with no experience and none of the fancy technology that Abby had.