"The general hope was that the roller ship would slash travel times by virtue of its low-drag design. Sadly, an attempt to cross the English Channel in 1897 revealed that the roller design had one unforeseen drawback. In the water, the rollers tended to drag a great deal of water up with them as they rotated."

Super fun. I'm a marine engineer and design vessels. I've seen a lot of whacky designs over the years and never encountered this one!

Apparently, from the above quote, the culprit for increased drag was skin friction (in this case, that meant water clinging to the surface of the rollers and being lifted out of the water - kind of like the reverse effect of a Tesla turbine which exploits skin friction between moving air and a stack of rigid discs on a rotor). That would certainly cause propulsive inefficiencies.

However, from my view, the primary source of drag here are the "hollows" between the rotor discs. If you were to look at a plan (top) view of the vessel as it moves through the water you would find significant water pressure gradients between (at the aft and fore end of) each wheel. When you have multiple wheels in series, you have oscilating high and low pressure zones along the length of the waterline. That's a tremendous amount of energy lost to water turbulance.

When you look plan views of hydrodynamic hullforms at the waterline (whether monohull, or multihulls like catamaran/trimarin/SWATH) or even aircraft foil shapes, you don't see "wavy" form lines for this very reason.

I will say that these inventers were encroaching on the SWATH hull shape. The author states that this roller disc hull would not be stable due to the high CG. However, SWATH hulls are known for their stability in high sea states.