In Defense of Skinny Boats

In an earlier post I defended simplicity. That got me to thinking that there are other things worth defending. Take skinny, or if you prefer, narrow boats. Before we got so technically advanced that we could squeeze a gozillion horsepower out of a small powerplant, boats were narrower. It was the only way to make them fast.

Pushing a boat brought the water with brute force is one way to do things. Damn the hullform, beam, or egregiously large, dock swamping, sailor-stands-with-fist-shaking wake that results. Build it and they will come, they say. So technical advances enabling more power has become a self licking ice cream cone. Before the consumer, and therefore industry, developed a blood lust for MOARRR POWER designers had to approach the problem differently if they wanted a boat to go fast.

Take the amazingly skinny TURBINIA, built in 1897. Design and naval architecture giants Uffa Fox and Donald Blount have both written about this remarkable vessel that helped pioneer and advance the thirst for speed at sea. TURBINIA was 103 ft long and had a beam of… wait for it… 9 feet! She did 35kts with a single 2,000 hp turbine. The thought of a modern vessel 100 feet long doing 35 kts with 2,000 hp is simply crazy, because nothing like that exists. Our unquenched appetite for space (i.e. beam) that creates the ‘required’ interior volume for all our stuff precludes it.

Dave Gerr, another prominent designer who probably couldn’t draw an ugly boat if he tried, makes the case for skinny boats in his great book The Nature of Boats that I previously reviewed here. He offers up NEEDLE, a single step hull that brings 70 kts with only 800 hp at 54’ LOA and a beam of 6’6”. You could argue that’s too narrow to be practical, but if speed is your thing, who cares? Doing 80 mph with 800 hp in a 54′ boat and better yet not needing a 747 load of fuel to do it is tantalizing!

But like America’s waistline, our boats expand to a point they look like somebody forgot to say ‘when’. Can’t fit your his and hers sinks with sauna shower in the full beam master? No problem! Make the boat wider! We can still make it bulldoze through the water with more power! But it doesn’t end there. We can squeeze all sorts of design tricks into that already bulbous, distinctively un-svelte hullform by adding multiple chines, re-drawing topsides with convex sections instead of concave. Sea keeping? Dry ride? Bah humbug. Give me more beam! Can’t you see that I’ve got to fit a full sized washer and dryer in there that will never get used?

Will we ever see skinny boats again? Unless powered by oars or a sail, where efficiency really counts, probably not. At the heart of the issue, every boat is a compromise, but we’ve been conditioned to expect speed and be able to have all our stuff. But, if we are willing to do without some of our ‘stuff’, imagine the possibilities with sensible modern power and a skinny hullform. The mind boggles.

 

4 comments

  • I think Turbinia had one boiler, but three turbines, each driving a shaft, each shaft fitted with three screw propellers. I’m not clear on whether the shafts were connected to each other mechanically, but the turbines were connected in series for steam flow, so the three turbines comprised a triple expansion ‘engine’.

    • Thanks for stopping by and for the comment Mike. In Seaman Like Sense in Powercraft Uffa Fox noted that there were cavitation issues with her original single shaft concept, and then switched to the 3 shaft, 3 prop per shaft configuration. He says “She was arranged with a high pressure turbine on the starboard shaft, the intermediate on the port shaft and the low pressure on the centre shaft, this centre shaft incorporating an astern turbine.” Fascinating and heady times for powercraft evolution indeed.

  • Great post! We love skinny boats! Not that Celeste is nearly as skinny as Turbinia, but compared to modern sailboats she’s wee 🙂 Especially in the stern! Lovely curvy butt 🙂

    • Thanks guys. As I re-read that post now I realize I came on a bit strong on the issue. I’m certainly not advocating a length to beam ratio of 10 for recreational boats but I do think we could skinny down the beam in some cases and reap the rewards of doing so. As for your boat, it’s dead sexy. I love that hullform because it places seakeeping as a high priority…

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