Ultra efficient boats

[JSH]

I would go with a displacement hull over a planning hull. They are far more efficient if you are willing to go slow.

Sailboats are also quite cheap - especially if you get to the size where they can't be trailered and have to have a slip or dry stored in a marina. People will just about give away a 20 - 30 foot sailboat to get out of the storage or slip fee.

[freebeard]

[Last Post: Ultra efficient boats 06-21-2022 02:29 PM]

It's never stopped us before.

a swim ladder or platform to launch from a beach

What would that be like? The best example of the roof I remember is this:



Maximum surface area for solar and it could retract into a tonneau cover. Unless you have a boathouse the roof would have good solar exposure. How many nautical miles in a week? You might be able to ride for free. It would need an efficient motor.

Just imagine this with toroidal props.

Candela C-POD | The world's most efficient boat motor

[freebeard]

So I followed that video to this one:

Candela Tech Talks | Episode 1, C-Foil System

A twisting wing hydrofoil for steering coupled with active ride height. What's not to like?

[ttrainxl]

Originally Posted by freebeard

What would that be like? The best example of the roof I remember is this.

What would a swim platform be like? They’re mounted on the lower area of the transom to make boarding easier. If launching from a beach or something other than a dock, it’s an easy egress into the boat.



This is a hard dodger for a sailboat. Often dodgers are just stainless bows wrapped in sunbrella cloth with vinyl windshield material, which would also work. But I’m picturing something that keeps you dry and warm and out of the wind and rain. The original poster is in Canada as I remember so protection from the elements is important for a commuter and goes beyond a cloth roof over your head.

Yes, a displacement hull can be pretty efficient, but I think the poster said he wanted something faster than sailing or displacement hull speeds. If the commute is ten miles, you don’t want it to take 1.5-2 hours, which is what would happen in a sailboat. In calm water. With no strong headwinds or adverse current. And if there is current, it will always go against you sometimes. Six knots minus a two knot current is four knots, which means over two hours for a ten mile commute. That would suck.

[redpoint5]

Originally Posted by JSH

Sailboats are also quite cheap - especially if you get to the size where they can't be trailered and have to have a slip or dry stored in a marina. People will just about give away a 20 - 30 foot sailboat to get out of the storage or slip fee.

Hope that holds up. Took a sailing class over a decade ago as a first step toward my retirement plan of sailing the world. Figured petrol would be $100/gallon when I retire, so I'll use free wind. Figured I could engineer an automatic sailing system combined with GPS to skipper the boat as I sleep (it will be a commercial product well before I engineer it).

In the other thread, it has me thinking how much joy I would get living at sea off the coast of CA, paying no state taxes at all, but enjoying every remaining enjoyable thing about CA.

Perhaps when I cease having an income, I'll identify as an indigenous trans Californian and reap whatever reparations I'm owed.

[ttrainxl]

This is a hard dodger I made for my 14 foot camp cruiser. I don’t have the windshield material in it in this picture, but you get the point. This is just luan plywood sheathed in fiberglass cloth and U-bolted to the stainless frame. It’s super light and a flexible solar panel goes on top. For a commuter, I think you’d make it twice as big for more cover from wind and rain, and for more space for solar panels, though if using an engine rather than an electric motor, you wouldn’t really need a solar array.

I don’t know how to make photos larger. Can someone help me with this?

[ttrainxl]

Originally Posted by redpoint5

Hope that holds up. Took a sailing class over a decade ago as a first step toward my retirement plan of sailing the world. Figured petrol would be $100/gallon when I retire, so I'll use free wind. Figured I could engineer an automatic sailing system combined with GPS to skipper the boat as I sleep (it will be a commercial product well before I engineer it).

In the other thread, it has me thinking how much joy I would get living at sea off the coast of CA, paying no state taxes at all, but enjoying every remaining enjoyable thing about CA.

Perhaps when I cease having an income, I'll identify as an indigenous trans Californian and reap whatever reparations I'm owed.

Sailing and living on a boat is a lot of work. I busted my rudder in Cuba this winter and Cuba had nothing to offer to fix it. I dove on the rudder and strapped it with scrap metal and have to haul out in Florida somewhere to fix it. Can’t sail confidently until I do that. So many things broke in Cuba, including my windvane ( the “automatic sailing system” you refer to in a way, but think you’re more talking about autopilot.). Checking your anchor five times a night in a storm during driving rain and not getting sleep because your hatches and port lights developed a leak and everything in the boat is wet and being in seas too rough to cook real food gets old pretty quick. It’s not all tits and sunshine like you see in the movies.

[redpoint5]

Originally Posted by ttrainxl

Sailing and living on a boat is a lot of work. I busted my rudder in Cuba this winter and Cuba had nothing to offer to fix it. I dove on the rudder and strapped it with scrap metal and have to haul out in Florida somewhere to fix it. Can’t sail confidently until I do that. So many things broke in Cuba, including my windvane ( the “automatic sailing system” you refer to in a way, but think you’re more talking about autopilot.). Checking your anchor five times a night in a storm during driving rain and not getting sleep because your hatches and port lights developed a leak and everything in the boat is wet and being in seas too rough to cook real food gets old pretty quick. It’s not all tits and sunshine like you see in the movies.

You make the adventure sound worthy of my attention. Do go on.

I have no contempt of nature, or for the physical properties of material science because they have no agency. Those challenges are best suited to my disposition.

All that said, the SeaDoo Spark is pretty darn efficient. I'm reading about 3 gallons per hour at full throttle, probably for the 60HP motor. I'd want the 90 for ability to pull a tube. Still very efficient.

[freebeard]

Since I can't get anyone to watch the video at #33, here's a transcript:

0:00 Thanks to our C-foil our boats are the most efficient boats ever made.
0:05 When flying in 20 knots.
0:07 The consumption is only one kWh per nautical mile,
0:11 which is roughly like 0,1 liters of gasoline.
0:16 In 20 knots, you can foil for two and a half hours
0:19 or reach 50 nautical miles.

[ttrainxl]

Originally Posted by redpoint5

You make the adventure sound worthy of my attention. Do go on.

I have no contempt of nature, or for the physical properties of material science because they have no agency. Those challenges are best suited to my disposition.

All that said, the SeaDoo Spark is pretty darn efficient. I'm reading about 3 gallons per hour at full throttle, probably for the 60HP motor. I'd want the 90 for ability to pull a tube. Still very efficient.

I wonder what it burns at a leisurely (for a Seadoo) 20 knots. Maybe 1 g/hr? A 32 foot 15000 pound trawler with a decent Diesel engine usually burns 2-3 gallons an hour averaging 8 knots. And you can make coffee and breakfast sandwiches and bacon while you’re under way.

I would think a lightweight 15 foot commuter boat fitted with an 18 hp two cylinder diesel like my Columbia sailboat had would plane at 15-18 knots and burn less than 1/4 gallon an hour. At 15 knots, 1/4 g/hr is 60mpg. Actually, 60 nautical mpg, which is 72 statute mpg. One nautical mile is 1.2 statute miles.

Wow freebeard, I’m gonna have to watch that video now! I thought when you mentioned foils, you were talking about those electric foil boards, basically like Marty McFly’s hoverboard but with the “keel” or whatever with the motor at the bottom. Skateboard sized basically, which would suck on a rainy winter commute in Canada. But a real boat with that efficiency sounds awesome. Watching in a sec! Sounds expensive!