Ultra efficient boats

[BeeCee]

I thought this might be a good place to ask.

Has anyone ever found info on tiny, super fuel efficient watercraft? People brag about 5mpg (or nmpg ) in their cruisers but I'm CERTAIN there must be misers out there who have managed to squeeze much better out of tiny, aerodynamic, underpowered ones.

Anyone?

[wdb]

[freebeard]

Welcome to Ecomodder.

...tiny, hydrodynamic, underpowered ones? As usual, the use case is a constraint. Speed/range, capacity, deck area.

Here's a technique for massive ships that should scale down:

KRISO Technology for Ship Propulsion Efficiency Improvement and Propeller Noise Reduction

Catamaran for deck area. www.youtube.com/results?search_query=tech+ingredients+catamaran

https://www.youtube.com/watch?v=6BMskpsLiYA

How Many Solar Panels Do You Need For A Trolling Motor?

klbuckyians.blogspot.com/2009/03/mechanical-jellyfish.html

One of his [Buckminster Fuller's] early inventions was a mechanical oar patterned after the motion of jellyfish. "It consisted of a tepee-like cone mounted on the end of a pole and resembled an inside-out umbrella. Standing at the rear of his boat, Fuller would pull the pole toward him through a large iron ring attached to the rear of the boat. As the peak of the umbrella-like invention pointed toward the boat, it displayed little resistance. However, when it pushed backward into the water, the cone opened, propelling the boat forward."

[BeeCee]

Those are excellent starts, thanks! I'm surprised i didn't have an account here already, I've been tweaking my Insight and other vehicles for years based on threads here

Cutting sailboats seem pretty natural to mention, but part of my hairbrained motive was to convince my partner we should look at house further along the coast and get a commuter boat into Vancouver, BC, to evade the horrible traffic (and avoid living in a tiny cramped condo close to her workplace).

That idea died when I read about the fuel efficiency of boats at more than a crawling/wind pace. But my curiosity remains

[freebeard]

So.... two to four passengers, short range. All weather year round performance.

Would you have a boathouse on the home end?

M-hull:

https://www.soundingsonline.com › news › m-hull-new-thinking-in-boat-design
M-hull: new thinking in boat design - Soundings Online
Thanks for watching! "The M-hull eliminates the speed limitations of displacement craft," says M Ship co-founder Chuck Robinson. "It's a major breakthrough in hull design because the more pressure is captured in the hull tunnels, the higher the boat rises out of the water, the faster it goes and the less draft it has.".

https://www.brighthubengineering.com › seafaring › 57366-learn-about-m-hull-technolgy
Designing Ship Hull - What is M-Hull? - Bright Hub Engineering
M-hull technology is an innovative development that uses a specifically M shaped hull to create an air cushion below the vessel in order to reduce the air drag. The M shaped hull captures the bow wave energy to form an air cushion, which thus reduces the drag. The reduction in drag provides exceptional speed to the vessel, a trait that ...

[cRiPpLe_rOoStEr]

Originally Posted by BeeCee

Has anyone ever found info on tiny, super fuel efficient watercraft? People brag about 5mpg (or nmpg ) in their cruisers but I'm CERTAIN there must be misers out there who have managed to squeeze much better out of tiny, aerodynamic, underpowered ones.

Not sure what would be "underpowered" to your standards, but I don't believe most of the leisure boat owners would be so willing to use a noisy and shaky horizontal-single Yanmar (or its Chinese copies) that I still see often on small fishing boats. Well, there are some boats fitted with such engines used as regular passenger transport in a touristic area in Florianópolis, but it's a very specific circumstance.

[BeeCee]

willing to use a noisy and shaky horizontal-single Yanmar (or its Chinese copies)

Do they get fantastic fuel economy ?

Not sure what would be "underpowered" to your standards

That part is certainly optional. I was operating on my experience with cars that have great economy.. tend to be called underpowered by others. I'm perfectly happy with the acceleration on my 1 liter honda Insight and my old vw van which have both been described that way. I guess the point is it doesn't have to get up to speed fast... Perfectly willing to trade that off.

[freebeard]

I was perfectly happy with the acceleration on my old [1961] VW van.

Extractor exhaust, dual Solexes, a really low first gear and it weighed about as much as a Beetle. The (hole shot) 60ft times were awesome.

(30mpg)

[cRiPpLe_rOoStEr]

Originally Posted by BeeCee

Do they get fantastic fuel economy ?

Those water-cooled horizontal-single Diesels are often reported to be quite efficient in general, no wonder they're still widely used for small tractors and some small fishing boats. Had them been too bad, they could at least literally serve as boat anchors, because they're quite overweight

I was operating on my experience with cars that have great economy.. tend to be called underpowered by others. I'm perfectly happy with the acceleration on my 1 liter honda Insight and my old vw van which have both been described that way.

28 years ago this model was praised as "revolutionary" for introducing EFI to the Brazilian 1.0L-engined cars, with a Rochester TBI. Now it's often pointed out as "underpowered", yet it can still get the job done for many people.



Roughly the same engine, with a higher compression and port-injection, at that stage the power increase was around 42% still within the 1.0L class. A port-injection with the low compression was already rated at a 20% higher power than the older engine fitted with a TBI, but even the high-compression engine was already pointed out as underpowered.



I still remember when Ford only offered the 4-cyl 2.2L turbodiesel in the Ranger on fleet-specific versions, supposed that most customers would prefer the 5-cyl 3.2L turbodiesel instead. Nowadays most of the times I see a Ranger it has exactly the 4-cyl...

[redpoint5]

This thread needs to start by constraining the topic to the requirements.

These have piqued my interest, especially since my local reservoir allows battery powered vessels.