What Single Scull Should I Buy?

by Steve Gurney

Most scullers find that rowing in club or borrowed boats is about as satisfying as playing tennis with someone else’s shoes and racquet or skating with someone else’s skates. You’re not sure what you’ve got, they fit poorly and performance and satisfaction leave much to be desired. Of course, you can blame someone else for your underperformance but that seems small satisfaction on a daily basis.

A single scull, other than a purely recreational boat, is best viewed as a very personal piece of equipment. It should be matched to your size and weight and experience and be set up especially for you – i.e. it should “fit” you. And it should do that every time you row it, without rigging changes or damage made by someone else. And of course the right fit is important for competitive success. Much data shows that races are often won and lost by very small margins, often a second or two or less, and a boat suited to you may make the difference. Over time, the investment in one’s own single is a small part of one’s investment in the time and costs of rowing. Even if you are not a competitor, the right boat is more fun to row.

Boat design is, of course, a compromise between wetted surface, form drag and stability , which are the main influences on performance. Form drag is why displacement hulls like rowing shells, or “wakeless” launches, or Viking ships, are elongated – it is immutable physics that a longer waterline produces less resistance from wavemaking. Since length also adds wetted surface and friction with the water, there are limits. A narrow boat requires less energy to push aside water to force room for its passage and to ease its return astern. There are other components to hull shape, of course, which will be a separate discussion.

Builders advertise their boats as lightweight, midweight and heavyweight. If one doesn’t know what these terms mean or why boatbuilders use them to describe their boats, then they are unhelpful or even deceptive. Foremost, they are marketing terms, to sell boats. They do not designate the boat’s actual weight on the scale, but summarize their design for designated weight loads - fudged, of course, by the marketing department. A lightweight with an advertised design weight range of, say, 130 to 170 pounds, may attract a broad range of buyers. The broader the range, the fewer different models a boatbuilder needs to build and therefore his capital investment and specialization and costs and inventory are lower. Nearly all boatbuilders agree that love of boats and of those who row them, and not profit margins, motivate their business and making boats seldom leads to a comfortable retirement, and so they want to keep their costs down. And since there is much competition between them, quality is consistently good. But boats with too broad a designated weight range are unlikely to be competitive throughout this range, since 40 pounds added or taken from a single scull’s load makes a substantial difference in its waterline and underwater profile. These factors in turn affect its efficiency in the water, and its stability affects the amount of pressure you can consistently apply to make it go forward rather than merely keeping it upright. Usually, the heavier the rower for the boat’s range, the more stable it is likely to be, and hence the faster you can row it.

One very knowledgable user suggested recently to me that the primary reason for the success and popularity of a particular brand of shell is its stability, which permits highly conditioned rowers to be able to hammer harder while wasting less effort keeping it level. A different manufacturer is advertising their single sculls as redesigned wider to increase stability, implying this should make them faster but which, of course, raises the question as to whether increasing width, aside from purely recreational boats, is in fact the best way to increase stability. Narrow boats, when stable, are faster.

When you step into a boat, your weight, whatever it is, should sink the boat into the water to its designed waterline. As suggested above and contrary to popular belief, stability in an elite boat is little influenced by the width of the boat, but much influenced by the height of the center of gravity in relation to its center of flotation, and by the cross section of the hull, whatever its width. With rowing shells, unlike most kayaks and some canoes, the center of gravity is always higher than its flotation, and there are no spinning bicycle wheels for gyroscopic stability, so our boats are by definition unstable. But the amount of it is what matters. To lower the center of gravity, flotation is reduced through shorter hulls – often 25 feet as opposed to 27. The shortest known competitive hull, apparently calculated by tank testing, is 22 feet three inches, by a German manufacturer, but a hull that short defies the physics of waterline length which nearly all the rest of us comprehend. In any event, a small amount makes a lot of difference. If you want to demonstrate that, at least if you are a lightweight, step into a midweight or heavyweight boat, see what effect your weight has, and row it. Then row a boat designed for your weight.

A ”midweight” designation with a load range of, say, 160 to 190 pounds, is probably unlikely to perform well with most women scullers or a lightweight male sculler. It will sit too high in the water with too much hull and windage and stability will suffer. Anecdotally, it seems purchasers tend to err on the side of buying boats with heavier capacity than would suit them best, which compromises efficiency through the water, stability and, of course enjoyment. Most heavyweight men, other than the real heavyhitters, would probably row most efficiently in midweight boats, at least as boatbuilders presently build and designate them.

From my experience, you should buy a boat where your weight would be towards the upper end of its advertised load range. That, of course, cuts down on the choices for us genuine lightweights. It seems builders don’t build, or at least advertise, single sculls designed for rowers in the, say, 115 to 140 pound range but believe they can widen the marketing appeal of their boats and increase their sales by building to a heavier upper range.

Double sculls can be different. At least three boatmakers build lightweight doubles which are essentially “stretched” heavyweight singles, and these are proven top performing choices for genuine lightweight men and women double scullers.

Hull construction and materials fall into two camps: honeycomb and carbon skin. Honeycomb construction sandwiches a very light thick porous material between carbon outer surfaces bonded on each side of it. This provides local stiffness but is irrelevant to the boat’s overall stiffness which must be obtained through its design and structure. Carbon skin boats are just that, thin skinned with one or more layers of carbon fiber where needed. They tend to cost more because their construction is more hand-labor intensive. Gel coat weighs more than paint, and the color red seems to weigh more than other colors, so paint, except red paint, is the choice of many rowers for that 10th of a second advantage over 1000 meters.

The hulls of carbon skin boats can be squeezed in by hand pressure when carrying, yet that characteristic may protect them in collisions because the hull flexes at the point of impact before it breaks open or punctures. Of course, if you feel your time has come to collide with a heavy object like a dock or a half submerged 55 gallon steel drum, the best rule to follow is to drill it head on with your bow ball. You may end up spread out on the front deck, but the force of impact is distributed through the whole structure and you may escape with no visible damage except to your ego and maybe not even that if no one saw you. Glancing blows or running the boat’s bottom up on a rock or dock are likely to peel back skins or make punctures you don’t want, especially with non-forgiving rigid skin honeycomb boats. These also tend to absorb water into the honeycomb itself, which carbon skin cannot. Statistical evidence is slim because the industry does not make use of crash test dummies so boatbuilders are free to make any claims they want. None known, however, seems to make claims not based on fact and their own anecdotal experience .