Comments by "Dave Sisson" (@Dave_Sisson) on "The Architecture of Dreadnoughts - Blueprints of Success" video.

Did one of your ancestors serve on HMS Gloworm?
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Trimarans turn well, but they are not as stable as big catamarans. Have a look at the big 110 to 130 metre cat ferries built by companies like Incat. Scale them up a bit and put on guns wherever you like as stability is not an issue on a large cat. They travel at 40 to 55 knots and are powered by water jets which are not as vulnerable to being shorn off in shallow water as azapods.
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@John.0z Well the only other maker of really big cat ferries, Austal, has a more pure SWATH configuration for their hulls, while Incat combines SWATH with several other measures for their wave piercing bows especially on their ships around 110 metres long.
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Hulls on large (over 100 metres) wave piecing catamarans like those built by Incat have a slightly hour-glass shape. They are more bulbous below the water, fairly thin on the waterline and then they widen again above the water line.
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@John.0z Both companies have improved the ride of their big ferries a lot in the last 25 years, the newer ones are surprisingly smooth. But some only have a cruising speed of around 35 knots, while others are closer to 50 knots which obviously affects the ride. In photos you will see that ships from Austal and Incat look quite different at the front. Which has the best ride is subjective, but overall I slightly prefer Incats.
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@John.0z They briefly tried a fast cat on the Tasmanian route over 20 years ago, but the stability tech was less advanced back then and it got nicknamed "Spewcat". If you're near Melbourne, there are a couple of much smaller 35 metre Incat boats on the Port Phillip Ferries routes from Portalington to Docklands and Geelong city to Docklands. They depart from just behind the main train station, although service is suspended during lock down. https://www.portphillipferries.com.au
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