I am not sure, but IMHO the article refers to
sailing not
rowing. Anyone can row a boat, but sailing... I wouldn't even know how to get the damn sail up.
You pull a piece of rope right by the mast and when the sail is up, you tie it up. It would probably take you whopping 1 minute to figure out. The rudder on small sailing boats go the opposite way of where you point them, so 1 minute to figure that out as well. You will probably be becalmed a couple of times and have the boom(?) (long stick connected to the mast that the bootom of the sail is fastened to) hit you over the head a couple of times, but otherwise, you would get the hang of it pretty quickly.
Even bigger ships could probably be sailed by noobs, with less sail and at a snails pace and not against the wind.
Remember, sailing was something you got press-ganged into doing!
... So, my conclusion is that having skills that say: "you can't do this without the skill" is just not right. Of course you can do it! Most likely very poorly - depending on how complex it is, but you can do it.
For instance, if you had access to a smithy, you could most likely make arrow-heads, spear heads and so on, while making chain mail or swords just wouldn't be successful.
In other words, when describing the skills, I think they should mention a lot of the things you could do untrained, what you could do untrained but poorly, and what things you could do if trained.
... I think I just came up with a skill system without bonuses, to dice throws, but descriptions of what you could most likely do. Take the sailor example, you could have three levels: novice, apprentice and journeyman. A novice could row a boat ok and sail a boat poorly. Trying to run a ship would probably end up in disaster. An apprentice could row a boat well, sail it decently and run a ship poorly. A journeyman could do all those things well.
To differenciate between the apprentice and journeyman when it comes to for instance sailing a boat, you could say that the apprentice would have to roll to see how well it goes if there is any stress, while the journeyman doesn't have to roll at all.