Ultra efficient boats

[ttrainxl]

It’s also worth noting that marine diesels are very expensive. I was quoted $18,000 for a new 3cyl Yanmar 25hp for my current boat. Beta diesels are marinized Kubota engines and are way cheaper. The same 3 cylinder 25 hp Beta would have been $6000. This is without transmissions.

You can get used engines from dilapidated sailboats for $1000, sometimes less. Look for a boat in the 28-30 foot range for a 15- 20hp diesel. For the price and effort, you may just decide to use a gas outboard. Not as fuel efficient, but cheaper and tons less work to install. Tohatsu has cornered the market for fuel efficient, affordable, and reliable small outboards. My 33ft boat is now powered by a tohatsu 9.9, rather than the expensive yanmar or other diesel.

[cRiPpLe_rOoStEr]

I noticed those small Diesel engines prices skyrocketted in my country too. Maybe the lack of Diesel small cars in junkyards tends to drive the prices of such engines, pointed out as more "specialized" and mostly targetted not only to the boating segment but also to the agricultural machinery and industrial applications. When it comes to gasser outboards, it's worth to notice at least Honda claims its current generation of outboards has a high degree of parts commonality with its car engines, which eventually may lead to an easier maintenance...

[redpoint5]

Originally Posted by cRiPpLe_rOoStEr

Honda claims its current generation of outboards has a high degree of parts commonality with its car engines, which eventually may lead to an easier maintenance...

I have that complaint about the entire industry. Why does there need to be so many parts? A company needs like 2 steering wheels, because it needs to be about the same size and shape as all steering wheels. There should be 10 standard brake pads (or something), because all brakes operate on the same principles and one could simply upsize the the precisely perfect set did not exist within those 10 sizes. There should be 10 sizes of air filters and oil filters, etc.

The whole industry is dumb.

[JSH]

Originally Posted by redpoint5

I have that complaint about the entire industry. Why does there need to be so many parts? A company needs like 2 steering wheels, because it needs to be about the same size and shape as all steering wheels. There should be 10 standard brake pads (or something), because all brakes operate on the same principles and one could simply upsize the the precisely perfect set did not exist within those 10 sizes. There should be 10 sizes of air filters and oil filters, etc.

The whole industry is dumb.

The industry caters to people that buy new cars - which is a species that you don't understand. If I recall your idea of a great car is one that is mechanically sound but cheap because it has extensive cosmetic body damage.

Cars mostly sell on style not practicality or ease of maintenance. People don't want to buy a car that looks like the car they bought or leased 3 years ago - which means continuous change both inside and out.

[freebeard]

Originally Posted by ttrainxl

For the price and effort, you may just decide to use a gas outboard. Not as fuel efficient, but cheaper and tons less work to install.

https://ecomodder.com › forum › showthread.php › alfadan-654-hp-inline-four-39430.html
Alfadan 654 HP inline four - EcoModder.com
2 Jun 2021Alfadan 654 HP inline four. one meellion dollars in crowd-sourced money, backing of Mahle and Freevalve, a proprietary 'connecting rod solution' and a running two-cylinder prototype. Porsche partners with MAHLE and TRUMPF to 3D print pistons ...

REVOLUTIONARY new INLINE 4 - ALFADAN BIG BLOCK i4 ENGINE

No www.alfadan.com/updates for two years.

Cars mostly sell on style not practicality or ease of maintenance.

aerohead's 'Paris dress-makers'.

[ttrainxl]

Pretty interesting video. I could certainly see that engine becoming very popular in the boating world. But I think the original poster is looking for a small boat with a small engine. I pictured a 13-16 foot runabout that’s easy to dock in tight spaces and crosswinds and lightweight enough to tow on a single axle trailer behind a four cylinder car.

I have a Dyer 12.5, which is a sailboat hull, that I got for $250 and without a rudder, rig, and sails. Actually without a trailer too. It weighs 200 pounds and the seller and I tossed it in the back of my truck. It occurred to me to find a small sailboat diesel and retrofit it as a small fishing boat that could go an entire season on one small tank of diesel. Lots of work would have to be done to make it an inboard, but the top of the motor cover would double as a workstation, as is the case with many small inboard fishing boats. This is really not too much different than a small commuter boat. Just add a couple more seats and maybe a windshield and cover (the dodger) for inclement weather. I think it would be a fun build. I love fiberglassing! (Sometimes)

[ttrainxl]

One other thing to note is that electric propulsion in small and medium sized boats has gotten fairly popular. Torqueedo makes electric outboards and inboards, and has systems to drive boats upwards of 100ft. Their small outboards from 2-20hp are pretty cool. Much more costly than a gas outboard, but all the benefits of electric. Your range has more to do with how many batteries you want/need. Li-Ion would be the way to go for weight savings and discharge capabilities over lead acid. Also costly though.

https://www.torqeedo.com/us/en-us/products/outboards

Sorry to post so many times in a short span. I think this concept is interesting and I’m addicted to boating! Check out some boats shows for some ideas. Not quite the right direction, but the WoodenBoat show in Mystic CT is coming up at the end of June. It’s a wonderful event and there are lots of vendors to look at. Many wooden boats get retrofitted with electric propulsion, but they have small diesel vendors there as well that are happy to answer many of your questions, and boatbuilders from all around the country go to the show, so any questions about hulls and ideal this and that could also be answered. I’d like to go again this year. Have skipped the last couple years. Newport is also a huge show with tons of stuff to consider.

[freebeard]

tiny, super fuel efficient watercraft....

That's a pretty broad remit.

...my hairbrained motive was to ... get a commuter boat

The kayak and hydrofoil are right out. Were I to show up in a major city in something. I'd want a stylish passenger shuttle pod thing* on a SWATH[ull] with rimdrive thrusters.

https://mil.ufl.edu › publications › Andrew_Gray_Azidrive_25sep2015.pdf
Azi-drive: a Novel Thruster Mapper for Twin Propeller Maritime Vessels
Two independent azimuth steered rimless propellers provide propulsion for the vessel. Using a nonlinear control allocation with singularity avoidance method, the approach was tested with simulations and then implemented on an ASV.

*Else a Geo Metro on pontoons? Solar electric of course.

[redpoint5]

Meanwhile, I'm wondering if supply chain issues have been resolved to the point that jet skis are being built again.

My recent "this or that" contemplation is between the electric hydrofoil or a 4-stroke stand up jet ski. Nearest lake I can take an ICE boat is an hour away, while the nearest reservoir that I can take electric craft is 10min.

Hydrofoil is cheaper, would potentially get a lot more use, and is portable inside a normal vehicle. Potentially less fun, slower, lower range, less of a full body workout, can't just "refuel".

Back to this thread, I think a commuter craft is an excellent idea. I assume it needs to be covered though, due to all the rain.

Something like this is what I'd be looking at

[ttrainxl]

Yeah Redpoint, I was also thinking of something small and lightweight like this, but possibly fitted with either a small Diesel engine or torqueedo electric propulsion and a sitting room only windshield/partial roof. A hard dodger that is used on a sailboat would be perfect. Flexible solar panels on top. That would also provide protection for gps, a stereo, etc if desired, and a steering console with a dashboard would make it feel like you’re “getting in and driving”, but you could still have a swim ladder or platform to launch from a beach and rod holders and whatnot for recreational boating as well.

Wonder if the original poster is still here. Haha.