Speed Over Water Goes Up and Up 
The idea of going places nautically fifty years ago was to build a veritable splinter of a hull, load it full of steam engine, have the crew part its mustaches in the middle, and, after roping down the safety valve, open the throttle and pray that nothing got in the way before the boiler blew up. If it were possible to dig up a movie of a high-speed craft of the nineties, the audience would probably think that it was watching the approach of the day of reckoning, well enveloped in dampness.
The best history of the sport in its modern sense is that provided by the results of Gold Cup races, which date back to 1904. The narrow-beam, displacement type of hull was then still in vogue, but the power plants were internal combustion and pulled from 25 to 125 horse-power. The winning speed that year was 23.6 m.p.h. Speeds increased slowly as higher power engines were developed, but the displacement type of hull was a glutton for power, while Scotch on speed. Just prior to the outbreak of the World War, speeds started upward—rapidly. Power had not increased materially, but a real advance had been accomplished in hull design. In fact, that advance was the first important one made since Casper Cornelius Caveman conceived the idea of sharpening the forward end of his log raft. It was, as everyone knows, the hydroplane.
The hydroplane reversed all previous theories of hull design. Where the lines of a displacement craft had been faired to the utmost to ease its passage through the water, hydroplane lines were designed to make the hull fight against passing through the water and climb up on the top. The knowledge that air was only one eight-hundredth as dense as water was being put to good use.
By 1919, the hydroplane, along with peace in Europe, was well established. Speeds in the Gold Cup race were hovering around the middle fifties, and the first high-power aircraft engine had made its marine debut. The following year, by virtue of the adaptability of the light-weight plane engine to multiple screw installations, speed popped up to an even 70.
From that time on, development was more in power plants than hulls. The rapid expansion of the aircraft industry encouraged lightweight motors while the automobile engineers were learning how to pull horses through higher revolution speeds. During this time, nothing of note was being done with hulls except a short fling at multiple-step bottoms which was merely a compromise, and not an advance. Several owners of displacement type hulls, caught in the grip of the business depression, "shingled" the old boats in order to get back in the running against some of the newer single-step hydroplanes. The results were equal to the performance shown by the one-steppers, but the shingled boats wore out and the idea died with them.
It seems an odd quirk of fate that boat-racing fans were at Lake George in 1914 watching the first real contest between a fleet of hydroplanes when they heard the first news of the invasion of Belgium. In 1939, the clans descended on Detroit to watch the first Gold Cup contest between a pair of boats of another new design, and there they first learned of the invasion of Poland.
This new idea in hulls was far from revolutionary—it had been tried (and rejected) by many an architect. But in 1936, the Apels of Ventnor really went to work on the design. In principle it was simple: instead of the boat riding on two planes, one forward, and the other directly behind it, the Apels tried running on three planes, two forward and separated athwartships, the other aft, and running on the solid water passing between the front two.
Today, all our fastest inboard craft are built to this design, or some slight variation of it. Speeds in the various classes have risen a-plenty since the perfection of the Apel bottom, and this without any material improvement of the power output of gasoline engines. Mort Auerbach's 225 record with an old-type hull was 64.7. Today, with almost the identical engines, boats of this class are knocking at the door of the nineties. The 135's have climbed from 53.6 to 67.4. The Gold Cup, or 732 cubic-inch class, could boast of a mere 76.08 four years ago while Lou Fageol's latest attempt was at the rate of 97.7 miles. The unlimited mark, the while, has crept up from 124 to 141. All of the new standards were set up in boats from the Apel board.
Along with this increase in intrinsic hull speed, there has come no paralleled rise in accidents. The three-point (more properly "three-plane") type of hull is inherently more stable than the conventional hydroplane because it has its points of support more widely separated than was possible with the older design. The Apel hulls are harder to upset for the same reason that a boxer is steadier on his feet, when they are separated, than when his heels are touching. The two disadvantages of this style hull have been pretty well overcome at the present time. The first is a tendency for the wide, tunnel-shaped bow to act as an airplane wing and lift at high speed, prying the whole outfit over backwards. This spectacular but uncomfortable sort of "wing-ding" has been discouraged by changing the aerodynamic properties of the forward deck. The other drawback, a structural weakness of the two forward planes, which are attached as appendages to the main hull, is not yet completely cured. However, it is probably no worse than the habit other types of boats have of smashing various and sundry parts of their bottoms at high speed.
What the future will be in hull design and construction is a bit difficult to predict. Unquestionably, we shall see an improvement even over the three-pointers. It is quite possible that further experimentation will lure us all back to the old, hydrofoil principle (demonstrated years ago) where none of the hull proper rides on the water. Although "foils" are barred by present racing rules, if owners could be shown that they, or any other wrinkles, would yield decidedly higher speeds per horsepower, the rules would soon be relaxed.
New materials for hull construction hold real promise. Waterproof resin-bonded plywood has grown rapidly in popularity for racing-boat use during the last couple of years. Builders are practising diligently in its use, and the day is probably not far off when we shall see it used for planking surfaces of all shapes, whereas now it is pretty much taboo on compound curves. Plywood has a high strength to weight ratio and is a labor-saver in application due to its being available in large sheets. Wood fastenings have undergone considerable improvement of late with the perfection of Everdur, Monel and stainless steel. The superiority of these alloys over the old copper and galvanized iron is so marked that the construction of a racing hull with the older sort of screws and bolts is a waste of money.
Metal hulls have hovered on the outskirts of practicability for racing purposes for more than a decade. So far, the cost has been prohibitive, and the completed models have not been very encouraging. A special type of plant is required for their assembly, and almost no boat yards are properly equipped. The best compromise to appear was that displayed in the Baglietto hulls brought over by Theo Rossi, where the frame work was of metal (welded tubing in one and extruded shapes in the other) while the planking was wood.
In the line of power plants, our future is probably brighter than with hulls, thanks to the war-like propensities of certain European gentlemen. It appears that each nation is trying to outdo the other in the speed with which they can fly into the other's backyard and drop bombs on various civilian chicken-coops and rabbit hutches. To achieve this all-important speed through the atmosphere, more and more horsepower from less and less weight has become essential. In our own country at the present time, we have in production liquid-cooled engines (the only type suitable for boat use), which are publicly admitted to develop 1,000 hp. If the whispers can be trusted, several times this output is available in single units. Concretely, we should shortly be able to buy, assuming the possession of sufficient pelf, engines of some four times the power of the old clunkers now for sale.
There are two main developments in the motor accessory line which should assist in this improvement. Super-chargers, which are something of an old wheeze, have been worked on very intensively of late and are coming into more frequent use on the marine speedways. The other line of attack is that of gasoline injection, a wrinkle now being given a fling on flying motors, and with very beneficial results from all the tales you hear. Ten years hence you can probably count on supercharged, gasoline injection engines as being fairly common in the more expensive classes.
In the accessory, or installation field, the speed fiends have really received only two boosts in recent years, but those were both of great help. As engine powers increased, it was found to be harder and harder to transmit the power to the propeller and, if anything, still more difficult to keep propellers together after the power reached them. The shafting difficulties were substantially reduced by using various nickel alloys. Chrome nickel steel, and to a greater extent, Monel metal, came into common usage for shafting. A more recent Monel type of alloy, which includes a bit of aluminum, has proven even more satisfactory for this use, until we now never give much thought to shaft breakages except when there is excessive driftwood to be driven through.
The propeller difficulties were greatly pared at the time Gar Wood started work on the latest Miss America—the one with four engines. Federal-Mogul made some studies which revealed that the thrust stresses and centrifugal stresses in an ordinary propeller were in the same direction. Added together they played hob with blades at high speed. A bit of clever designing accomplished a redistribution of mass which placed these stresses in opposite direction so that they tended to counteract each other. The first models from the new design were much slower than their older, but more fragile cousins. After a few years of experimenting on the Miss America, George Reis' El Lagarto, and some others, the new, so-called "Equipoise" propeller can go just as fast as its predecessors, at the same time staying together.
We may hope for two decided improvements in this accessory field. The most important will be to remove the propeller shaft, struts and other high-resistance appendages from beneath the hull. The answer may be an outboard drive affair, but whatever it is, elimination of the resistance of several yards of shaft, bulky struts, etc., will surely speed us up. The other thing to be desired is a change in the type of rudders. Streamlining of under water appendages for high-speed work is futile—we just "gotta" get rid of them.
The final aid the speed merchants should add to their Christmas lists is a photo-electric timer. The need for such a device is apparent when you consider that, at 120 miles an hour. an error of one-tenth of a second in timing causes an error in speed of .399 miles an hour. Still we blithely quote speeds in thousandths of a mile an hour when the timer pushing the button is probably not accurate to anything like one-tenth of a second.
(Reprinted from The Rudder, May 1940, pp. 18-19, 80)