Inside Angle: Paths of Propulsion
Among the many conversations I will have as a yacht designer at the upcoming Newport and Ft. Lauderdale boat shows, I guarantee these two will take place:
One: Me to electric powertrain supplier: “What do you say to a boatbuilder who wants to install electric power into production 40-footers that can cruise at 30 knots?”
Electric powertrain supplier: “Tell them to go away and come back in ten years.”
Two: Boatbuilder to me: “We want to install electric power into production 40-footers that can cruise at 30 knots.”
Me: “Modern engines are underrated.”
While we live in an era overflowing with powertrain choices for boats of all sizes, with the exception of the EPA-stifled large diesel market, fully electric planing powerboats may not be ready for prime time now or in the foreseeable future.
The old adage that “electricity and water don’t mix” is still partially true when it comes to recreational marine propulsion. There just is not a commercially-available battery technology in 2024 to feed motors that will push a vessel through the water, or thrust it up on top of the water, with an appealing mix of speed and range. You think a road trip in a Tesla requires some planning ahead? How about the fear of running out of juice 30 miles off Palm Beach? That’s range anxiety.
I’m not a naysayer, mind you, just a seasoned realist. My office penned the world’s largest electric yacht in 2018, an 87-foot displacement-hulled classic with enough batteries to power eight electric BMWs. Two electric motors producing 90-hp each propel this clipper bow day yacht to a cruising speed of nine knots for around eight hours. Since she’s on a lake only seven miles long, there simply is no range anxiety. But that boat and her environs are a special case; low-duty cycle and a short leash.
There are more paths to propulsion for modern yachtsmen than ever before. Each have quirks and features.
In 2015 my office engineered the first-ever Huckins sportfish with pod propulsion, a retro-looking 37-knot fish magnet with an innovative layout for fishing and cruising. Spencer Yachts followed suit, building eight of their own boats with Volvo-Penta IPS power packages in the ensuing years. Paul Spencer is known to be a forward-thinking boatbuilder and he saw advantages in pod propulsion that not everyone agrees with. More often than not, though, skeptics walk away from a sea trial suitably convinced that pods can raise fish just fine.
Big, reliable outboards have produced a seismic shift in propulsion preference for many. Hanging five outboards off the transom of a dayboat has led us to a new word in our shared nautical vernacular: Quints. Quint is the natural progression of single, twin, triple, quadruple and quintuple engine counts. What comes after quints? Six engines. These are sextuples, or sexts. Sexts used to just be pictures that Brett Favre sent women from his phone, so don’t be too surprised when your wife gets her hackles up once you start telling her about your new sexts.
Diesel outboards are here now, up to about 350-hp if you don’t love the smell of gasoline vapors in the morning. Thus far your choices for diesel outboards 300-hp and larger are limited to COX or OXE. Are multiple OXE then OXEN? What about several COX? COXes? I should stop now.
Yamaha has been displaying a hydrogen-fueled outboard at boat shows this year. Sounds neat. But one look into the open 26-foot hull to which the motor is attached reveals three tanks. Combined, they hold the equivalent of a mere 25 gallons of gasoline. These three tanks are each the size of SpaceX rocket boosters and leave little room below deck for live wells, water tanks, or bilge pumps. These high-pressure tanks store hydrogen at 10,000 PSI. Electric range anxiety … hold my beer.
Maybe at some point far in the future scientists will invent a way to harness the wind to power boats with no fuel, no batteries, very low PSI and no range anxiety.
Ehhhh. Sounds boring.
This article originally appeared in the October 2024 issue of Power & Motoryacht magazine.
View the original article to see embedded media.
Source: https://www.powerandmotoryacht.com/column/inside-angle-paths-of-propulsion
