Electric Powered Boats

[N4061]

There is a new category under builders called Electric Powered Boats that I requested be established as we start our latest adventure.

Hope to see a few TF followers stop in from time to time, generate some discussion and provide comments. The intent is for this thread to be educational while we share what we learn along the way.

John T - Nordhavn 4050, 4061, 3522. Helmsman 38E - former owner
Marshal Marine Sandpiper - current owner

 

[JD Ray]

FWIW, I'll stop by and support your efforts with all the words I can generate.

 

[backinblue]

Suggest one of the mods combine/delete the 2 duplicate threads you started.

 

[JD Ray]

They appear to have moved at least one of them here.

 

[N4061]

Checking in

It appears this new thread is working and I'm glad to see a few other topics added. I'm already learning a lot from reading everything posted to date. While our adventure will be less daunting than modifying an existing trawler or purchasing a boat similar to the HH44 which was also mentioned in one of the posts we still have lots of questions and long way to go.

For those who are interested Plug Boats is a good website for information related to electric power and boats and many other related topics. There are a few interesting boat tests and videos including one of a boat getting up on skies as it glides "over" the water. OK, a little less hull resistance so better range "but" I still cannot see a Nordhavn 40 doing this while cruising an ocean. At least not yet.

A few observations I have made related to e-boats in our desired category include:
1. most have very narrow beams and look somewhat unsafe
2. most cruise along at 5 knots with 5 hours of battery capacity (additional batteries are optional)
3. most are limited to safe harbor cruising where current and wind are not a factor.
4. the larger boats (still under 25') do not appear to be trailer friendly
5. pricing range for new builds are about $50K - $100K depending on options and level of finish. Some boats are still all wood
6. Europe has a few more manufactures than the US and Canada and leading the way in technology. Same in the aerospace industry.

So, the education continues as does the adventure toward the next new boat build.

John

 

[N4061]

Type of Boat

As with each boat we build or purchase we start out with our intended use and the boats "mission". Many years ago, I wanted something simple to trailer and fish around southern California and purchased a new 21 Mako CC up north which we enjoyed for many years. When we decided to explore trawlers we had dreams of heading to Mexico and Alaska in addition to living aboard part time. The result was our Nordhavn 40's. When we wanted a simpler boat to test the waters after being away for a few years we purchased the N35 then built the Helmsman 38E. When Mary decided, she was done boating I decided to try something different and had Geoff at Marshall Marine in Maine build me the Sandpiper. With this boat in the garage and still needing to learn how sail I find us using the boat under power more than with the sail up. I'm not ready to give the sailing thing but I am ready for something else that will help keep Mary on the water with me when the weather is nice.

A few requirements for the next boat include includes a high quality, safe, trailerable boat with classic lines for a few hours of cruising. That was easy but the next set of requirements is where things get interesting quickly. If was just myself, I would likely look at another center console but if want Mary to get out on the water we need more comfort so a boat that provides protection from the wind and sun. I also recognize that speed is not important (remember those trawler days) or is significant power.

When I start adding all this up and think about the electric OB we used on the Gig Harbor dingy I think an electric boat make sense. As many know I enjoy researching and tweaking designs of boats so this could be fun. I looked at just about every boat built in the US and Europe a couple of years ago and came close to building one but it didn't fit all my requirements. Fast forward to today and with the recent advancements in technology I'm optimistic we find a manufacture to build us the right boat even its a new design or modification to something existing.

The fact that I want a safe boat that handle large bays and occasional runs outside the breakwater to the next harbor will likely stretch most boats capabilities and make this an interesting pursuit. Reading other posts related to an electric trawler are definitely the other end of the spectrum for our plans "but" the basic requirements are similar. Fun stuff.

John

 

[JD Ray]

The fact that I want a safe boat that handle large bays and occasional runs outside the breakwater to the next harbor will likely stretch most boats capabilities and make this an interesting pursuit. Reading other posts related to an electric trawler are definitely the other end of the spectrum for our plans "but" the basic requirements are similar. Fun stuff.

As a Class C boat, it won’t handle going out over any breakwaters, but have you looked at the Revo 870?
https://www.naturalyachts.com/nexusrevo870electric

The extended range version with an 8.5 kW motor will go 24 nm at 6 kts in four hours of cruising. For its size, it’s got nice room inside, and I can’t imagine there’s much maintenance (no complicated systems like your average trawler).

 

[N4061]

Thanks for sharing

As a Class C boat, it won’t handle going out over any breakwaters, but have you looked at the Revo 870?
https://www.naturalyachts.com/nexusrevo870electric

The extended range version with an 8.5 kW motor will go 24 nm at 6 kts in four hours of cruising. For its size, it’s got nice room inside, and I can’t imagine there’s much maintenance (no complicated systems like your average trawler)

Interesting boat, thanks for sharing. As you pointed out she may not be designed for anything except relatively calm waters and is something I'm finding out with most designs. With the smaller boats (under 24') they are either very narrow or the hulls are designed for almost flat clam waters. I found some very nice boat built in the UK but again they are mostly on the narrow (beam to length ratio). Problem coming from trawlers is I'm spoiled with the large beams. The search continues...

John

 

[N4061]

Nordhavn 40 Retro-fit

I was speaking with a representative of an electric motor company who mentioned his company supported the retro-fit of N40 Wing Engine with an electric 10KW motor designed to be powered off the 8KW Generator. Owner wanted to ditch the Yanmar and was pleased with the results. Speed range with the electric motor was reported between 3.8 - 4.0 knots. Not far off what we experienced on our two N40's.

I cannot verify the information above but found it relative and from a trusted source. This makes me wonder when builders will start offering electric wing engines as an option moving forward.

John

 

[twistedtree]

I was speaking with a representative of an electric motor company who mentioned his company supported the retro-fit of N40 Wing Engine with an electric 10KW motor designed to be powered off the 8KW Generator. Owner wanted to ditch the Yanmar and was pleased with the results. Speed range with the electric motor was reported between 3.8 - 4.0 knots. Not far off what we experienced on our two N40's.

I cannot verify the information above but found it relative and from a trusted source. This makes me wonder when builders will start offering electric wing engines as an option moving forward.

John

Yes, I recall someone doing that. It would be interesting to follow up and see how it is working out. I'll see if I can dig up anything.

 

[N4061]

Next Boat

The more I search electric boats the more time I spend looking at builders in Europe where there are significant advancements are being made. Since we are not looking to "go fast" we are focusing on the canal / river style boats and quickly discovering they are relatively narrow. A few have wider beams and offer some high-end finishes, but nothing designed for possible "coastal cruising". This has me looking at a few sailboats and thinking what we could do.

If this approach sounds familiar it should since the first Nordhavn (N46) was basically designed around a sailboat hull. What if we could find the perfect sailboat hull and add a deck that would meet the mission we have planned? Already have one in mind and investigating further. Fun stuff.

John T.

 

[backinblue]

Something like this?

 

[boathealer]

The more I search electric boats the more time I spend looking at builders in Europe where there are significant advancements are being made. Since we are not looking to "go fast" we are focusing on the canal / river style boats and quickly discovering they are relatively narrow. A few have wider beams and offer some high-end finishes, but nothing designed for possible "coastal cruising". This has me looking at a few sailboats and thinking what we could do.

If this approach sounds familiar it should since the first Nordhavn (N46) was basically designed around a sailboat hull. What if we could find the perfect sailboat hull and add a deck that would meet the mission we have planned? Already have one in mind and investigating further. Fun stuff.

John T.

A sailboat's gonna be rolly and needlessly "deep" if used as a slow trawler. If going this route, I'd rather consider a catamaran - same (likely better) lenth to beam ratio of hull(s), less rolly, less depth, two small motors vs. one, etc.

JMHO,
R.

 

[mcarthur]

The more I search electric boats the more time I spend looking at builders in Europe where there are significant advancements are being made. Since we are not looking to "go fast" we are focusing on the canal / river style boats and quickly discovering they are relatively narrow. A few have wider beams and offer some high-end finishes, but nothing designed for possible "coastal cruising". This has me looking at a few sailboats and thinking what we could do.

If this approach sounds familiar it should since the first Nordhavn (N46) was basically designed around a sailboat hull. What if we could find the perfect sailboat hull and add a deck that would meet the mission we have planned? Already have one in mind and investigating further. Fun stuff.

Hi John, that's one reason why we bought a larger power catamaran. The hull is designed for power not sail. Ours is pretty narrow in both senses - less than 5m beam means it's suitable for most European/French canals, and the length-beam ratio is about 12:1 which is good for speed through the water.

If you can say more about what you mean by "coastal cruising", as well as your expected location, it may be clearer whether you could "get away with" a monohull, with/without flopping protecting, or whether a multi may be better.

 

[Hippocampus]

When talking about “sailboat hulls “ need to define what type of hull. Now of historical interest only there were full keeled sailboats. I assume that’s what you are referencing. That form was given up over half a century ago (with the exception of island Packets-now defunct). Full keeled sailboats are exceptional slow due to increased wetted surface and parasitic drag. They point poorly and do poorly in survival conditions. Hence the public and industry moved on. Deep Water says it developed it’s hull form as an evolution of the Volvo Race type hull but critical exam shows little relationship.
The mandates on a powerboat hull are quite different than for sail. Mode of emotive force is different. Sail needs a righting arm to counteract that portion of wind generated force that doesn’t contribute to the vector that moves the boat forward. Sail further needs appendages that generate lift to counteract the leeward force. Power doesn’t have these constraints. Both those constraints generate drag and there’s no reason to include them in a power vessel. For power a righting arm sufficient to allow a safe Gz curve is adequate. This can and is usually developed in the absence of appendages. Multihulls use form stability rather than a weight at some distance below the canoe body to develop that righting force. But even there the constraints and optimal hull(s) is quite different. Look at a Tenant and compare to a Outremer or Gunboat. Propulsive force on the sailboat is the vector aimed forward. It is the fraction of the total vector developed from the wind. Ultimately that forward vector fraction is communicated via standing rigging. But so is all the vectors that don’t contribute to propulsion. One not uncommonly sees asymmetric hulls as a response to these needs on sail multis. No need to do this for power. For power it’s simply the forward vector developed by the props. This difference has meaningful effects on optimal hull form, weight distribution, needed structure to resist the propulsive forces (and other stress vectors). Although you see many series production multi hulls offered as sail or power I continue to believe those designed from the ground up for its primary mode of propulsion are usually better suited for that mode of propulsion.
No escaping physics. Boats are best designed from a totally clean piece of paper. Taking into account propulsion, type of service, and needs of operators.

 

[backinblue]

How is Island Packet now defunct? Also, they may not be the fastest boat, but have been known to win some bluewater races.

https://ipy.com/

 

[Hippocampus]

They folded in 2017. Now under new ownership. My understanding is although their website shows the old full keel designs none made in quite some time. Full keel sailboats are of historical interest and not great sailors. IP tried to compete with the non full keel “Blue Jacket” I’m curious can you name one sailboat race they won in the last 40 years?
Their 45’ has a phrf of 126. Whereas a Outbound 44/46 is 90. The outbound has a similar purpose -blue water cruising not racing. I had to give them 36 seconds per mile. No island packets are very slow so lost their appeal to the cruising market. They never were in the racer market.

 

[rslifkin]

They no longer make sailboats. I’m curious can you name one sailboat race they won in the last 40 years?

Island Packet is definitely still building boats. Not many, but they did get rescued when they were going under a few years ago.

 

[backinblue]

They folded in 2017. Now under new ownership. My understanding is although their website shows the old full keel designs none made in quite some time. Full keel sailboats are of historical interest and not great sailors. IP tried to compete with the non full keel “Blue Jacket” I’m curious can you name one sailboat race they won in the last 40 years?

Their website sure looks like they are still making full keep sailboats. Also there is this from a recent Bermuda race. I'm sure there are more, but this took 10 seconds to find and I'm not really interested in debating. I'm not disagreeing that they are not the fastest sailboat, but that's not why people buy them.

https://bermudarace.com/finisterre-division-winner-orca-sweet-surprise/

 

[backinblue]

one more for good measure...

https://www.capitalgazette.com/cg2-arc-be2d5a09-d76b-5452-88e5-8fac7934dfe6-20120621-story.html

 

[Hippocampus]

I was wrong IP built one 360 in 2012 and a 439 in 2021. So technically they are still building full keel sailboats. However still standby my statement the market has moved away from full keel sailboats. They have been a minor anachronism for decades.

Have done that race multiple times. You are given a time allowance depending upon how fast or slow your boat is. I lost my class to another boat that came in a day later than me one year. I don’t wish to argue as well but IP sailboats are considered slow by most and the data supports that opinion.

 

[rslifkin]

I was wrong IP built one 360 in 2012 and a 439 in 2021. So technically they are still building full keel sailboats. However still standby my statement the market has moved away from full keel sailboats. They have been a minor anachronism for decades.

Have done that race multiple times. You are given a time allowance depending upon how fast or slow your boat is. I lost my class to another boat that came in a day later than me one year. I don’t wish to argue as well but IP sailboats are considered slow by most and the data supports that opinion.

They've also built a handful of Bluejacket 40s, but yes, I agree. They're a very niche market at this point. But more importantly, it's not just that there's no demand for a boat like they build. It's that there's no demand for it at the price a new one costs.

 

[Hippocampus]

A typical cruising sailboat has a PHRF around 90-100. Race boats are now in negative numbers. Comparing my last boat (90) to the same size IP I have to beat him by about 6.8 hours (leaving from Newport) or about 7.2 hours (from Marion) assuming we both sail our boats to their maximum capabilities and we can stay exactly on the great circle. Reality is typically times will be greater. Those are using distances of 680 & 720 miles. Actual distances are usually greater. So even for a typical coastal hop up and down the US east coast the IP will show up days later.
My next door slip holder during 2013-14 was on a IP460. We’d leave together to go to block island. Usually a reach. Even on his best point of sail with me not racing he’d show up 1/2 to 1 hour later. On a beat 1-2hours later. IPs are slow. Is what it is. Very well made boat but SLOW.
Returning to power boats there’s no reason I can think of why one would want a powerboat based on a slow sailboat hull when there are so many better choices available at any given price point.

 

[backinblue]

I was wrong IP built one 360 in 2012 and a 439 in 2021. So technically they are still building full keel sailboats. However still standby my statement the market has moved away from full keel sailboats. They have been a minor anachronism for decades.

Have done that race multiple times. You are given a time allowance depending upon how fast or slow your boat is. I lost my class to another boat that came in a day later than me one year. I don’t wish to argue as well but IP sailboats are considered slow by most and the data supports that opinion.

Aren't most sailboat races handicapped by the rating of your particular boat? If not, most races would not be much of a race at all. I agree that the market has moved away from full keel sailboats. But they still have some positives and appeal to certain sailors and certain missions, just like full keel trawlers. See what I did there? lol

I do respect your experience and opinion Hippo. Just out of curiosity, what model sailboats have you owned and preferred?

 

[Hippocampus]

Outbound 46 my favorite
A one off used for single handed transatlantic racing. I converted it into a cruiser. Still too high tech and bare bones with too much spaghetti for family so sold. A scalded cat. Easy to keep at hull speed or better but needed continuous tweaking to get the best out of her like any race boat.
Tayana cutter. Used coastal and blue water. These have gone rtw more frequently than any other design. Strong boat.
Pacific Seacraft. Use primarily coastal with just a few passages.
Cape Dory- several sizes.
Mariner 36 a good near shore boat. Did one Bermuda in her and she did quite well.
Various small boats including part ownership of a J24.
Have crewed a lot of others.

Sailboat races are divided into
Open- no time allowances. Virtually all RTW and most involving all professionals are open. Even the America Cup could be considered open. Some rules concerning nature and limitations on construction are involved but otherwise they are open to any new advances.
Class- no time allowances as all boat the same
Rated= phrf is the most common as rating system is for a given area like New England.

Some pure amateur races do involve time allowances like phrf but the class races don’t.
Overall it’s a mix. Suspect, but don’t know, it’s pretty even split.

 

[Bob M]

Looked at the Northman. Nice boat. The cabin headroom is over 6.4 ft., a big plus for me. The downside is the beam, 9.5 ft: it's not trailerable without permits, one for every state I'd want to tow through.

 

[JD Ray]

Looked at the Northman. Nice boat. The cabin headroom is over 6.4 ft., a big plus for me. The downside is the beam, 9.5 ft: it's not trailerable without permits, one for every state I'd want to tow through.

There are, as far as I know, scant few “trailerable trawlers”, and the ones that are out there are pretty expensive for what you get. I’m lucky enough to live on the coast, so don’t have to worry about that.

I reached out to Northman and asked them for a quote on a boat delivered to the PNW. Their response was essentially “sorry, we’re so busy building boats for our local market, we can’t even think about delivering something abroad.”

Europe is ahead of us in several ways, one being the demand for eco-friendly cruisers.

I think it’s been a couple years since I did a straw poll on TF about how people used their boats. The vast majority of respondents said they cruised for six to eight hours, then parked for a day or two before cruising either to their next destination or back home. It seems that an electric range somewhere in the 48-64 nm zone would satisfy those requirements. Even if the solar installation was only sufficient to provide house power for a 24-hour period, it would be feasible to go from place to place on all electric, with a recharge of the main batteries at each destination. If there’s no grid-tied (e.g. marina) recharge capability, then running a generator (say 30 kW) for a couple hours will recharge the batteries sufficiently to get to the next destination. This, to me, is far better than burning diesel for eight hours plus whatever time at destination you need to for house power. The design of the Northman supports this paradigm, and I wish more boat builders would… ahem… get on board.

 

[twistedtree]

If there’s no grid-tied (e.g. marina) recharge capability, then running a generator (say 30 kW) for a couple hours will recharge the batteries sufficiently to get to the next destination. This, to me, is far better than burning diesel for eight hours plus whatever time at destination you need to for house power. The design of the Northman supports this paradigm, and I wish more boat builders would… ahem… get on board.

People want to be Eco friendly, so buy into this without understanding that it actually consumes MORE fuel and generates MORE byproducts vs running 8 hrs on a diesel.


Physics is everywhere, but not understood anywhere.

 

[LandlockedInUT]

People want to be Eco friendly, so buy into this without understanding that it actually consumes MORE fuel and generates MORE byproducts vs running 8 hrs on a diesel.


Physics is everywhere, but not understood anywhere.

The part I find particularly laughable is the oft-mentioned idea to use a generator to generate AC, then rectify it to DC to store in the batteries, then convert it back to AC to run the motor.

Something, something, laws of thermodynamics... I dunno.

 

[mcarthur]

The part I find particularly laughable is the oft-mentioned idea to use a generator to generate AC, then rectify it to DC to store in the batteries, then convert it back to AC to run the motor.

Something, something, laws of thermodynamics... I dunno.

Hmm, noone I know wants this. If a genset is mentioned it's always DC, variable speed. And you know there are such things as DC electric motors I hope?

So solar and genset creates DC, going into DC battery, then to DC motor. The bad boy obviously is the diesel genset, if you have/need one.

Ya'know, the part I find particularly laughable is to dig deep into the ground in law abiding, peaceful countries to collect disgusting black stuff called crude oil, heat it to 400 degrees Celsius and fractionally distill it, add extra stuff into it so it works better for us, transport it around the globe in huge ships burning a form of oil, then burn it up in an diesel engine that is at most 45% efficient - and ours are likely much less. Oh, and the exhaust is carcinogenic to humans. I dunno.