I watched the video clip of the 'device', and was unimpressed. (In fact I was tempted to use a much less flattering word.) In a small, eminently scullable boat, the gent in question was doing less than half the boat speed he would have achieved if he'd taken the time and trouble do learn to scull properly, with no more effort and much more elegantly than his clunkety clunk progress.
There's a strange mystique around sculling, I suppose because few people do it these days. It isn't difficult. It's a knack, like riding a bike, rowing effectively etc. Some people find it easier than others (remember those first attempts on a bike, and your friends got the hang of it quicker than you did? - mine did, anyway). It needs practice and perseverance at first, until you do it without thinking about it. In my mid teens, staying with a friend who lived in Gorran Haven (Cornwall), we messed about in an old, heavy clinker-built rowing boat, and by the end of the fortnight we could get up a fair turn of speed sculling, and manoeuvre round and past other craft. The final laugh may be on me, but I hope that it will come back to me, as bike riding does even after years. I hope that my 12 ft Trouper, once built, will be scullable with an 8 ft oar. It should work, says he ever the optimist.
A yuloh is a long sculling oar as refined for bigger boats by those clever Chinese (remember, this is your resident junk rig freak speaking). This is one area of human activity where size really does matter. Simon mentioned the length a yuloh needs to be, and I think this is the biggest obstacle. Plus you guys with (relatively) big boats have more to move: and you further complicate things with your mizen masts and suchlike. The 'tenders' (I don't know what they called them- certainly not that!) of Thames barges were about 15 ft, sculled with an oar which was probably 12 ft long. So, unless you can stow a really long yuloh aboard, or think of a way to make it sectional and still strong enough in the loom, it's back to discussing the relative merits of electric or ICE outboards.
However, if you get the chance to scull, do try it and persevere with getting the knack. It's fun, and potentially useful.
(SP Cadenza)
