Here They Come

I am buying my second electric vehicle. I would welcome an electric boat in life just from reduced maintenance. The practicality of owning an electric boat will vary from owner to owner. We'll have choices in the marine industry for decades. Look at heading up into the remote areas we do where there is no plug/showre power to plug in and recharge. There's not enough solar capacity on the top of a CD to recharge what we use for our passages. It's so early for the marine industry however, think of how far we have come in the automotive industry and where we are headed there. I could see some sort of a hybrid system for those that want to travel into remote areas. With a generator to supplement the electric/battery. Love the creative and out of box thinking that is going into installations. I have a client right now working on a battery bank for an all electric sail boat. However, those systems aren't being designed around a planing hull. It's an exciting time for innovation and change!
 
Foggy":3iclxtjr said:
... Maybe good bye to 'Slow - No Wake' zones? ...
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Depends on whether the "No Wake" zone is actually to protect from wakes or for speed control in confined areas.

Probably $300K+.
 
The Swedes are doing it big time; recreational craft and small commercial.

https://www.cnn.com/2022/06/28/business ... gfooterold
Have a look.

As mentioned, "going green" doesn't come cheap up front but the operational
costs may be reduced "90%". Mother Earth is not too impressed since most
marine harmful planet emissions come from the big ocean going freighters not
conducive to this technology, yet.

Change isn't coming. It's here.

Aye.
 
For C-brats the conversion is easy if you are willing to forego the high speeds. A couple of 3kW outboard motors will move my C-Dory 22 cruiser at speeds up to 6.8 mph. My cruising range is 50 miles at 5mph with only 360 lbs of batteries.
The batteries fit in the space where the fuel tanks used to be. You can find the pictures in my album (WATT NOW).
 
Query the logic of designing an eboat with a planing hull (Ex: C-Dory) and
placing needed heavy batteries for range with a goal of cruising at 5 - 7 knots
and a top speed (to avoid bad weather, current, wind or seas) of not much more.

IMHO, the logic of "form follows function" says choose a displacement hull.

Aye.
 
Tom, a friend of mine has signed on as crew aboard one of the new electric ferries servicing Wolfe Island from Kingston Ontario. They are scheduled to begin service in about 2 weeks - after some problems and lots of delays. You can google lots of info on them but you might be interested in their charging system which consists of onboard and onshore storage. This allows very rapid DC to DC charging. Ontario is now planning to add them to the Toronto Island ferry run.
https://www.leclanche.com/wp-content/up ... 0.9.21.pdf

Regards,

Rob
 
I'm a strong supporter of electric propulsion but feel the optimal battery/motor/speed/range is still not there. The Arc-1 has a 220kW-hr battery and a 500 hp motor. If you could truly run at 500 hp, the battery would be depleted in less than 35 minutes. Now a boat that size would be launched into orbit at that power level. But a similar boat that size and weight would be equipped (conservatively) with 175 hp outboard which would deplete the battery in 1 hr 40 minutes. Performances that would still disappoint most boaters.

I use my 22' cruiser for salmon fishing off the Oregon coast in the summer. For me, an ideal setup would be to keep my 90 hp Suzuki (I need the power and speed crossing the bar and cruising to the fishing grounds) but to replace my gas trolling motor with an 'equivalent' electric thruster. I could replace one of the gas tanks with batteries. I would need to be able to run the electric thruster up to 10 hours per day and be able to charge at my slip from shore power. The quiet and vibration free trolling would be very pleasant.

My trouble with designing such a system is that the commercially available electric thrusters do not offer enough performance specifications. For example, I would like to know input power vs. Bollard thrust. Tom offers some good data on his setup but that is specific to his electric outboards and their propellers and speed.

I estimate I need roughly 700 usable amp-hr at 12 volts but before I would invest in such a system I need more technical data to do a proper design.
 
Karl Konecny":2y9q6l9d said:
SNIP The Arc-1 has a 220kW-hr battery and a 500 hp motor. If you could truly run at 500 hp, the battery would be depleted in less than 35 minutes. SNIP
Click to expand...

With weather patterns changing faster and being more severe, about a half hour
joy ride is going to be all you're going to get. So what's the problem?

Aye.
 
A few post ago, FOGGY questioned the choice of a planing hull for e-propulsion, and yes form does follow function. But the question is not whether the hulls is planing or displacement, but rather how much power does it require at the lower non-planing speeds.

All the information I was able to find indicated that the C-Dory 22 hull requires less power at the lower speeds than most other hull shapes. The flat bottom aft reduces the wetted surface and thus friction from water. This was confirmed when I started collecting data on my boat. The power requirements for my C-Dory match those I would have expected from a displacement hull of a similar weight and length. I posted the power curve in my album (WATT NOW). The curve matches the one I calculated from Dave Gerr's equations in his Propeller Handbook. (You can find the basic power curve and more information in my book "Plug-in-Boats: A primer for getting started" available at Duckworks boat Supply https://duckworks.com/ )

I did look at a number of pilot house displacement boats that are similar to the C-Dory, but all of them would have cost me a minimum of $15,000 more than the C-Dory. The former all would have had to be custom builds using wood and epoxy rather than fiberglass.
 
Karl,
I suggest you get a copy of my book I mentioned above to calculate your power requirements for converting to electricity. It all depends on what you want your trolling speed to be. You can start with the power curve I posted on my album for my 22' C-Dory. I expect yours would be very similar unless your total weight is much more than mine (about 3800 - 4000 lbs when cruising).
For example, if you want to troll at 4 mph your motor will need to put out about 1000 watts (+- 15% to account for variations in motor and prop). Forget about bollard pull if looking at trolling motors, and look for the actual power consumption in watts. In my previous boat, a 26ft St. Pierre Dory I used two Minn Kota 36 volt (112 lb) trolling motors. These are rated at a maximum of 1800 watts (50 amps) but they quickly overheated at this high output and had thermal shutdowns. By drilling holes and adding small (1.2 inch) 12V computer fans to the housing I was able to cruise at 5 mph for hours at 1200watts each.

I expect one 3kW epropulsion outboard (or something similar) would be adequate for your trolling if you plan to troll at 4 mph or less.

I was able to fit four 48V 100AH batteries in the two spaces reserved for the fuel tanks (see my album page). So if you are removing one fuel tank you have room for two batteries with a total energy capacity of 10 kWhours. This would give you about 9 hours of trolling at 4mph and about 20 hours at 3 mph.

Most larger 48 V battery chargers put out about 20 A so you could recharge from shore power in about 10 hours.

I hope this helps. Send me a message if you have questions.
 
While an electric powered boat would not be for me, many of us enjoy cruising at hull speeds. And there are many folks that can't do anymore than that anyway. In regards to weather and such, you plan accordingly. Many of my trips, cruising 6-8 hours at hull speed looks like would be easily doable with Tom's setup. And the batteries would weigh less than the gas at the beginning of the trip. The batteries will be a little more expensive in the beginning, but I'm sure a lot cheaper than the gas in the long run. To each their own. :) Colby
 
Tom Hruby":2ml3xyx8 said:
A few post ago, FOGGY questioned the choice of a planing hull for e-propulsion, and yes form does follow function. But the question is not whether the hulls is planing or displacement, but rather how much power does it require at the lower non-planing speeds.

SNIP.... the C-Dory 22 hull requires less power at the lower speeds than most other hull shapes. The flat bottom aft reduces the wetted surface and thus friction from water. SNIP
Click to expand...

Kudos for agreement that form follows function.

Please realize an underpowered planing hull eboat (Ex: a C-Dory) that cannot
exceed a speed greater than single digits would be considered unsafe in all but
calm seas with little or no ability to outrun or out maneuver worsening weather.

Displacement hulls, by design; i.e., more water friction, at these speeds are better
able to cope and maintain control in larger seas preventing excess yaw, roll, broach
and capsize than a flat hull vessel.

Aye.
Grandpa used to say, "When venturing offshore, away from the beach, power becomes
subservient to control and safety."
 
It all depends where one is cruising. My cruising territory is Puget Sound where I have been cruising for 26 years in three St. Pierre Dories which had a completely flat bottom, and I never have felt unsafe. in fact, the St. Pierre Dory is considered one of the safest small boats (they used to go the grand Banks with only a 1.5 hp motor) according to John Gardner who wrote the Dory Book.

There have been a number of discussions on C-Brats about the behavior of the C-Dories in heavy seas and the general agreement is that it is a safe boat it its size range (they are a favorite in Alaskan waters). Also, the consensus seems to be that one needs to slow down to 5-6 mph in heavy seas, and not try to power through them. With my two electric outboards I cruise at 5mph but do have the power to get up to 6.8 mph at maximum thrust.

Comparisons of the C-Dory 22 to other dory designs suggest the bow is basically that of a Swampscott Dory. The discussions I have seen also indicate that the 22 is better than many boats in following seas because of its flat bottom that provides a better initial "lift."

Cruising at or below hull speed in a power boat is similar to sailing. One has to be constantly aware of weather and tides and use them to advantage.
 
ssobol":3ahvwyih said:
More and more lakes are turning to electric only for allowed mechanical propulsion. Some places your boat can't even have a gas motor mounted on it, even if you don't use it.
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“Signs, signs…everywhere a sign. Do this. Don’t do that…can’t read the signs?” Oh, the irony. :roll:
 
Tom Hruby":2mqjefi4 said:
It all depends where one is cruising. My cruising territory is Puget Sound where I have been cruising for 26 years in three St. Pierre Dories which had a completely flat bottom, and I never have felt unsafe. in fact, the St. Pierre Dory is considered one of the safest small boats (they used to go the grand Banks with only a 1.5 hp motor) according to John Gardner who wrote the Dory Book.

There have been a number of discussions on C-Brats about the behavior of the C-Dories in heavy seas and the general agreement is that it is a safe boat it its size range (they are a favorite in Alaskan waters). Also, the consensus seems to be that one needs to slow down to 5-6 mph in heavy seas, and not try to power through them. With my two electric outboards I cruise at 5mph but do have the power to get up to 6.8 mph at maximum thrust.

Comparisons of the C-Dory 22 to other dory designs suggest the bow is basically that of a Swampscott Dory. The discussions I have seen also indicate that the 22 is better than many boats in following seas because of its flat bottom that provides a better initial "lift."

Cruising at or below hull speed in a power boat is similar to sailing. One has to be constantly aware of weather and tides and use them to advantage.
Click to expand...

Very sorry. Cannot let these C-Dory ideas rest, unopposed.

Safety aboard a boat is more dependent on the boat than the operator(s).
In a heavy following sea, a heavy low open transom is a good thing.
In a heavy following sea, a flat sterned hull providing lift is a good thing.
Slow speed in a power boat is similar to sailing.

Aye.
 
colbysmith":2px9830e said:
Safety aboard a boat is more dependent on the boat than the operator(s).
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Laughable at best! You can have the safest boat in the world, but the operator can still muff it up! You lost me Foggy...

Colby
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Yes, one way to get lost communicating is to cherry pick statements.
Your pick, and conclusion, does not consider the original prior statement.
:idea

Aye.
 
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