smallest sailboat which has an inboard engine

[urisvan]

hello,
what should be the smallest size of a sailboat but still she will have an inboard engine.
cheers

[ancient kayaker]

I've seen a sailing kayak equipped with an electric trolling motor.

[Doug Lord]

I had a 20' motorsailer with a 15hp yanmar diesel....700 mile range under power.

[masalai]

I can remember 14 to 16 ft double ender? lap-strake planked heavy rowing boats fitted with a little petrol one cylinder salt water cooled inboard operating in the "sheltered waters of what is now the Gold Coast around the 50's to haul nets out from the beach and everyone strolling along would help to haul the net in and get a fish or two as thanks for their help, also some were later available as hire boats for fishing/crabbing in the rivers....

[timothy22]

In the '70s I had an 18' lateen rigged flat-bottomed, long keel, double ended, decked over weekender with a 5hp Kermath. It had a standing well aft, and I pitched a pup tent on deck. They loved it in Tarpon Springs!

[urisvan]

I had a 20' motorsailer with a 15hp yanmar diesel....700 mile range under power.

thanks for different kind of examples. they are both nice.
but i am espacially interested in coastal cruisers. please send more examples.
doug lord, that sounds nice. what was the model of your boat?
cheers

[Doug Lord]

I had a 20' motorsailer with a 15hp yanmar diesel....700 mile range under power.

thanks for different kind of examples. they are both nice.
but i am espacially interested in coastal cruisers. please send more examples.
doug lord, that sounds nice. what was the model of your boat?
cheers

----------------------------
Hi urisvan-thanks. See this thread: http://www.boatdesign.net/forums/motorsailers/20-motorsailer-25454.html#post246500
I designed the little motorsailer based on an 18' daysailer/weekender that I had designed for T Craft boat company.

[urisvan]

thanks,
what i had in my mind is a sailboat, capable of going in heavy seas, maybe not in the ocean, but in agean sea, where there are high winds sometimes(not very big waves).

[masalai]

look at something like the smaller Lombardini 2 cyl inboard marinised engines - fairly light and seem quite popular in Europe.... 500cc and 700cc diesels....

[mattotoole]

I've read that a few Cape Dory Typhoons came with inboards, but I've never seen one. Can anyone confirm (or deny) this?

[PAR]

A Flica, would fit your request nicely.

http://newimages.yachtworld.com/1/5/5/2/2/1552247_1.jpg

http://home.att.net/~seagypsy/images/flicka_original_1.gif

http://home.att.net/~seagypsy/images/flicka_original_2a.gif

http://home.att.net/~seagypsy/images/flicka_original_3a.gif

20' on deck, standing headroom (5' 11"), 8' beam, 3' 3" draft and displaces about 3 tons. A good little sea boat by Pacific Seacraft

She's rough water capable and would be fairly comfortable, considering how short she is.

[masalai]

Hey, that is quite cute....

[peterBUILT]

Look at: International Folk Boat, or Cheoy Lee Frisco flyier.

[keith66]

Or there is the Anderson 22, Oliver Lee design, fast & seaworthy with lifting keel, mine has an RCA Dolphin 12 HP petrol inboard thats like having a smooth turbine under the deck. http://anderson22class.co.uk/

[JotM]

In order to round up some more ideas to chew on:

the North Beach 24 (http://www.northbeachyachts.nl/eng/nb24.htm)
or the Wadkrabber (http://www.wadkrabber.nl/home_english.html)

Both a bit longer, but able seaboats.

If I turn back to the original question, which I interpreted like "is there a minimum size for a boat to carry an inboard engine?", as a mechanical engineer I would say "No". One could probably use the smallest air cooled single cylinder diesel engines (like e.g. the Lombardini 15LD225, the Mitsubishi L2E or the Yanmar L48V) fitted out for a marine environment. At a weight of 25-35 kg you should even be able to mount that in a small beachboat. (with a max. power < 5 HP your boat shouldn't be a whole lot bigger ;) )

Cheers.

[urisvan]

thanks JotM,
i got it. actually my question involves another question inside it: what should be the minimun size inboard engine for a coastal cruiser capable of struggling in heavy seas, and then i should ask what is the minimun size of the boat taht can carry this size of engine.
yes, even i will navigate with sails mainly, an adequate size of engine that you can trust is necessary

[alan white]

My boat, a heavy gaff sloop of 15 ft, would be a prime candidate for an inboard of modest size (5 hp max). I personally don't care to go to the expense and add the extra weight, but I've toyed with the idea of the same hull and rig and a small overnight cabin. Then I suppose there'd be nothing preventing the installation of an inboard.
The question is really what is the smallest cruiser that one would take offshore (if only for small journeys), period. The engine, to be inboard, has to be small enough not to tax the displacement, and the keel/underbody/rudder must accomodate it.
In any small (under 18 ft, say) yacht, an inboard is definitely in the way of potential stores and accomodations. Particularly in light of the fact that small yachts can be rowed. And then, there are so many modern 4 stroke outboards of 2 -3 hp that are reliable and cheap and removable/carryable.

[JotM]

I agree with Alan!
Myself I am pretty impressed by the Cardigan Bay lugger (http://www.swallowboats.co.uk/content/view/95/30/) Swallow Boats has cooked up in this range kind of boats.

LOA 18'7" (5.7 m)
beam 6'2" (1.9 m)
displ. 550 lb (250 kg)
4 HP OB in a well
berths for two

[the making of and first use (http://www.swallowboats.co.uk/content/view/122/)]


Personally I am leaning more towards the sailing canoe or "raid capable" row&sail kind of craft at the moment. But a Swallow Boats "Storm Petrel" or CLC "Skerry" sounds a bit small for the usecase urisvan describes. :eek:

But, urisvan, I think you are facing a typical design problem here. It is not like one thing clearly defines the other. The size and displacement of the boat determines the power needed to propel it forward into rough seas. Which leads to a certain dimensions and mass of an engine. Which in turn make up a good part of the displacement of your boat. (the solution is part of your problem you might say) In the end it has to be in balance.
When I started designing ship cranes an old engineer said to me "construieren ist radieren" which is German and translates into "designing is erasing". I guess this is also such a case in which you just have to start trying and tweak as you go.

Regards.

[PAR]

I don't think it's practical to get much under 20' LOD for an inboard. Even though I have a 18' design that does, it's nearly three times the weight necessary for the output and takes up very valuable stowage room, with is at a premium on a small cruiser. When you can have a 2 to 5 HP outboard that weighs less then the battery to run nav lights, it's a fair big consideration.

A boat's ability to take to open water, with the safety I think you desire, is a pretty rare breed of pocket yacht. Flicka is an exception and one well designed to boot, but there aren't many like her.

Frankly, moving up a couple of feet (say 22') will still keep the boat small, easily managed and affordable, but at the same time, you'll gain huge amounts of volume and an inboard is a move viable option.

[ancient kayaker]

Though not an experienced sailor I too was impressed by the CB lugger. Only 250 kg weight fully rigged? Am I missing something?

[JotM]

Something like the "massive" weight of an inboard engine? ;)

[PAR]

. . . and the ability to take on occasional blue water, often found in coastal cruising, which is likely the hardest kind of sailing to do (both boat and crew) . . .

[JotM]

PAR,
Can you tell why this boat is lacking that ability to your opinion?

[JotM]

PAR,
Can you tell why this boat is lacking that ability to your opinion?

[urisvan]

par,
do you mean that; with the boat of these sizes, for example 20 or 22 feet, it can be hard to make blue water sailing even as a part of your coastal cruising?

[ancient kayaker]

Well, it looks like it's off the coast so I guess it's in salt water, but there's land close by in every shot except one, and that has a rowboat in it. I've encountered bigger waves in my canoe! But it's still a sweet looking boat.

[PAR]

EU RCD Category C is pretty much what every sailboat with a covered foredeck, reasonable coming and closed cockpit seating will be. Coastal sailing is about the hardest thing a boat can do. You'll see steep swells, confused seas, plenty of junk in the water that can hole your boat, lots of commercial traffic (which usually can't see you) and winds well in excess of the EU RCD cat C requirement., which is only 25 knots or so.

The CB lugger is a fine little puddle jumper, but I wouldn't ask much more of it then that. It could be overwhelmed by a decent thunderstorm, let alone a nasty contrary current in a confused 6' sea with a half a gale building. It's a wonderfully shaped boat, but I'd keep her quite close to shore.

Look once you get farther from shore then you can safety swim back to, you're in an unnatural environment. Meaning if something goes badly wrong, you chances of dieing increase exponentially. This is when you want a little ship under your butt, not a puddle jumper. You'll want a reasonable D/L ratio so you can tolerate the storm without heaving your lunch or having everything that once was on a shelf, now on the cabin sole. You also want the ability to carry on, off the face of a lee shore in substantial wind strengths without having your sticks blown off the boat. In short, you'll want more then a 500 pound boat under you for coastal cruising.

I've attached one of my designs. It's a real little ship, capable of offshore cruising and real voyaging. The short Bermudian rig and gaffer are shown. A taller Bermudian rig and a round bilge hull form are also available. A quick look at it's numbers and you can see she's not going to get her butt kicked nor be easily over whelmed. Of course she's not going to get up an plane off either. She has the internal volume to carry the stores and supplies for cruising, without having to sacrifice bunk space to stow gear. She's self righting too.

This is a little cruiser, abet with an old school charm. She could be done with a modern look too, but you'll still want similar features. A small boat can pound you to death in short order if the conditions are right. Why, when you can select a design that will look after you, rather then the other way around.

[JotM]

I think you designed a beautiful little craft there, PAR.

That being said, please don't be blinded by EU RCD categorisation. For instance, I see no guard-rail in your design, which immediately implies it would probably only qualify for cat C or D under the RCD (according to EN-ISO 15085). There are lots of different reasons to certify a design under a specific categorisation. I expect one of the most important ones is article 8 of the RCD (http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:31994L0025:EN:HTML), which implies that certification of a boat in category C can be done without physical testing as long as harmonized standards are adhered to, whereas category B always requires tests.

Now I am wondering. As we are talking/writing about coastal cruising, not ocean cruising, shouldn't we take into account the area in which the boat is intended to be used? The OP, urisvan, is based in Istanbul, so I guess the boat he is thinking about should be suitable for his regional waters. Myself I am based in Leiden, which is on the sandy North Sea shores of the Netherlands. Having "worked my way up the boating ladder of experience" from paddling an inflatable on a local canal to cruising the German Bight in a 26' sailboat, with less than 30 years you might still call me a novice. And in more than one aspect I think I still am myself. But if I had to choose between the Cardigan Bay and your design, I would go for the CB. I reckon my chances of survival in the short chop of the North Sea or "Waddenzee", when surprised by a storm, are bigger with the flat bottomed beach boat type. Then again, that's the kind of boats I grew up with.
But history gives me some reassurance as well. The hulls of the Swallow Boats Storm range (http://www.swallowboats.co.uk/content/blogcategory/13/30/) seem to decent from Norwegian double ender open boats. And those (http://www.oselvarverkstaden.no/index.php?option=com_content&view=article&id=45&Itemid=29)have cruised the treacherous waters of the North Sea and the northern Atlantic for quite a while now.

Cheers

Edit: removed pictures of more agile boats for coastal cruising, as they were clearly not cruisers in the way the other posters seem to mean.

[urisvan]

hello,
i will try to sum it up:
first the choice of our little boat suitable for coastal cruising is important. i share the same opinion with PAR. Coastal cruising in aegean means waves up to 5 metres and winds up to 60 knots. Oh yes i can handle this with my windsurf equipment but it is a different story. i think the weight is important as the PAR said. The examples that are given shows similarity, FLICA, FOLKBOAT and PAR design. they are all long keel boats. I quess it is(being long keel) necessary to obtain the weight required, the space for the accomondation and inboard motor. but i have only one doubt about them: i did not sail one of them but i heard that these type of boats have bad pointing ability. So can they easily escape from a lee shore in strong winds??

second the length of the our smallest boat (that is suitable for offshore) that can carry an adequate inboard engine. as JotM said that it is a design problem, but a starting point in design is important. and PAR said that it should be at least 20 feet and 22 should be better. it is very logical.

cheers

[JotM]

Sorry for being inconsiderate before. I should probably have realised earlier the Aegean Sea and its shores are deeper and steeper than the shores I am used to deal with.

I wouldn't worry about the reaching capabilities of the designs mentioned, at least not about the Folkboat.
There is one in my club and based on what I've seen in club races she reaches pretty good.

Lots of fun with whatever long keeled boat it is going to be.

Cheers

[apex1]

hello,
i will try to sum it up:
first the choice of our little boat suitable for coastal cruising is important. i share the same opinion with PAR. Coastal cruising in aegean means waves up to 5 metres and winds up to 60 knots. Oh yes i can handle this with my windsurf equipment but it is a different story. i think the weight is important as the PAR said. The examples that are given shows similarity, FLICA, FOLKBOAT and PAR design. they are all long keel boats. I quess it is(being long keel) necessary to obtain the weight required, the space for the accomondation and inboard motor. but i have only one doubt about them: i did not sail one of them but i heard that these type of boats have bad pointing ability. So can they easily escape from a lee shore in strong winds??

second the length of the our smallest boat (that is suitable for offshore) that can carry an adequate inboard engine. as JotM said that it is a design problem, but a starting point in design is important. and PAR said that it should be at least 20 feet and 22 should be better. it is very logical.

cheers

I am pretty shure that all three can escape from a lee shore. The "Folkeboot" does not provide a proper space to accommodate a Diesel engine (out of race). I do´nt know about PAR´s design, he does´nt show a prop in his sketch, but believe she can. The Flica has a big, big advantage, often overlooked, she provides enough space for a large prop! A small, low power (10 hp), high torque engine connected to it will get you away from trouble.
Just my two cent (0,02 €)
Regards
Richard

[PAR]

The prop aperture isn't shown because it's available as an outboard in a well (not my first recommendation) or a straight shaft inboard. The aperture is in front of the rudder, so flow is better as is steering (very similar to Flicka's).

Flicka is a little bigger then RYD-14.11 and displaces slightly more. Her numbers are similar, so both will be comfortable in a rough slosh and self righting.

The Bermudian rig is better to windward as you would expect, but the gaffer is quite respectable and can claw off too. The hull has to have enough "power" to do this, as well as good appendages and rig. Lighter boats can get "slapped back" trying to climb away from a lee shore, even if they are fine windward machines in softer winds.

Things I look at are maximum stability, enough displacement to permit reasonable comfort, enough volume to allow reasonable stowage space and balanced sailing lines, so she will not have any nasty habits, particularly when you really don't need them (like clawing off a lee shore). This doesn't produce the fastest boat, but it does generate a real cruiser. A boat that has the room to stow your gear, spares and stores, the heft to bash her way through if it comes to that and one who's motion, will rock you to sleep instead of knock your dental fillings out. These are the hallmarks of a cruiser. Now, some disagree and that's fine, but if you can't stow what you want to bring along, get pounded to death going to weather in a stiff breeze, have to worry about sudden and unexpected broaches in certain conditions because of hull shape and appendage decisions and aren't particularly comfortable except at anchor, then you will not be doing much cruising.

For those that think it's fun to surf down waves in 30+ knots and 10' seas, go for it, but I've found most that want a cruiser, can live without the thrill rides, preferring to stand watch with a cup of coffee on the deck, without fear it'll spill. In a cruiser, you should be able to leave the helm, grab a fresh beer from the cooler and walk easily back to the helm, without concern you'll round up hard enough to toss the crew below on their butt.

[apex1]

In a cruiser, you should be able to leave the helm, grab a fresh beer from the cooler and walk easily back to the helm, without concern you'll round up hard enough to toss the crew below on their butt.

And even worse ... to spill the beer!

So PAR, what´s your recommendation for the 14.11 ? Which engine do you think will fit?
Regards
Richard

[PAR]

The completed boat (double chine gaffer) has a Hatz 10 HP air cooled diesel, mated to a Japanese transmission, of which I can't remember the make. The whole assembly, engine, pump, trans, home made manifold, weighs less then 200 pounds and is a pretty clever arrangement, if you can tolerate the noise. Two more are under construction, one plans on using a well mounted outboard and the other is still debating how to approach the little inboard. Kubota has some nice, small diesels. Their Z482-E3B would be my choice. It's a 2 cylinder, 13.5 HP, 4 stroke, water cooled little puppy that weighs about 140 pounds all wet. It would be softer spoken, requires much less air volume through the compartment, but would be a fair bit heavier then an air cooled engine.

[apex1]

The completed boat (double chine gaffer) has a Hatz 10 HP air cooled diesel, mated to a Japanese transmission, of which I can't remember the make. The whole assembly, engine, pump, trans, home made manifold, weighs less then 200 pounds and is a pretty clever arrangement, if you can tolerate the noise. Two more are under construction, one plans on using a well mounted outboard and the other is still debating how to approach the little inboard. Kubota has some nice, small diesels. Their Z482-E3B would be my choice. It's a 2 cylinder, 13.5 HP, 4 stroke, water cooled little puppy that weighs about 140 pounds all wet. It would be softer spoken, requires much less air volume through the compartment, but would be a fair bit heavier then an air cooled engine.

The "Hatz" has a good torque, is almost indestructable but pretty loud!
The little "Kubota" is a real good engine too, but if the boat is used to "sail" I would go for the aircooled Hatz! No through hull hassle, no impeller to service in a very tight and cramped space, no winterizing, and so on.
Regards
Richard

[alan white]

Hatz, a south African company, has smaller diesels as well, in the five h.p. range I think. A light 10 hp diesel is going to shake a small boat. A Flicka sized boat is just about right for 10 hp, but a typical displacement 20 footer (and under) would be happy with 5 hp or thereabouts.
The Katz's best feature is price. If you can martinize it (provide cooling air and exhaust jacketing) and get a transmission reasonably, the air cooling (if loud) does away with a whole lot of maintainence. There are certain kinds of insulation that will cut down on cabin noise, but the cooling ducts will be hard to make quiet.
Still, as little as a blue water cruiser motors, it's an economical way to go.

[apex1]

Hatz, a south African company, has smaller diesels as well, in the five h.p. range I think. A light 10 hp diesel is going to shake a small boat. A Flicka sized boat is just about right for 10 hp, but a typical displacement 20 footer (and under) would be happy with 5 hp or thereabouts.
The Katz's best feature is price. If you can martinize it (provide cooling air and exhaust jacketing) and get a transmission reasonably, the air cooling (if loud) does away with a whole lot of maintainence. There are certain kinds of insulation that will cut down on cabin noise, but the cooling ducts will be hard to make quiet.
Still, as little as a blue water cruiser motors, it's an economical way to go.

Oh. oh ALAN...
Hatz is a German Factory established 1880!!! Not African!!!:mad: They have many branches abroad, even in Waukesha WI.
They produce 1 Cyl. engines from 3,5kw up to 11kw and 2-3-4 cyl. up to 60kw.
The most interesting engine is their "Supra Silentpack" :idea: 1 cyl. 13 hp for the intended use.
http://www.hatz.com/index.php?id=70
edit:
better this:http://www.hatz-diesel.de/index.php?id=70&L=1
Regards
Richard
if you go to Ruhstorf for a visit, stay at the "Antoniushof" Hotel, say regards from Richard, get the bridal suite for a single room rate.

[PAR]

I like the Hatz (German) little diesels. They don't spin way up, developing max torque at less then 2000 RPM, which is perfect for a fairly heavy small boat. I'm currently looking into a stainless steel, drive cable, that could be used as a coupling between shaft and transmission. This would eliminate the need for stiff mounts and the engine could be placed on soft doughnuts, which would dampen vibration and noise a good bit.

The flexible shaft is only good in low HP applications (maybe 20HP max), but just the ticket for mounting an off set engine and routing a drive cable around centerboard cases or other obstructions. Both Flicka and RYD-14.11 carry displacements that are typical of much larger craft, say around 23', instead of 20' and 18' (respectively). I did develop up a set of intake baffles for the air cooled engine which cut down on a lot of the noise, but it needs a lot more understanding about this dynamic then I have, to really make a huge noise reduction.

[JotM]

Just curious about the Hatz. Are you talking about the single cylinder here (1D41 or 1D42) or about the two cylinder (2W35)?

[apex1]

I like the Hatz (German) little diesels.


Hahaha, thank you, let me be proud about our industry sometimes;)

The "Silentpack" seems to be a sort of sufficient solution, at least the spec. sheet shows nice figures.

To the cable issue I have no idea. But sounds clever. Anyway these little Hatz one cyl. puppies do´nt shake soo much that you´ll spill the beer!

Regards
Richard

[JotM]

... Anyway these little Hatz one cyl. puppies do´nt shake soo much that you´ll spill the beer!


Whats makes you think PAR is talking single cylinder?

[PAR]

They have a number of single and twin cylinder engines under 20 HP. The engine installed is model 1B4OU2ES, which I think is superseded by 1D42.

Of course many changes had to be made. The tank was removed, a cold air pack installed, an exhaust manifold made, etc. None of this is especially difficult for a reasonably handy person. The bracketry was home made and welded, but the manifold was professionally welded.

[apex1]

Whats makes you think PAR is talking single cylinder?

Knowledge JotM, knowledge, the two cyl. Hatz in the 10kw range are watercooled and PAR was talking about a 10hp!
Regards
Richard

[alan white]

Oh. oh ALAN...
Hatz is a German Factory established 1880!!! Not African!!!:mad: They have many branches abroad, even in Waukesha WI.
They produce 1 Cyl. engines from 3,5kw up to 11kw and 2-3-4 cyl. up to 60kw.
The most interesting engine is their "Supra Silentpack" :idea: 1 cyl. 13 hp for the intended use.
http://www.hatz.com/index.php?id=70
edit:
better this:http://www.hatz-diesel.de/index.php?id=70&L=1
Regards
Richard
if you go to Ruhstorf for a visit, stay at the "Antoniushof" Hotel, say regards from Richard, get the bridal suite for a single room rate.

Thanks for the correction. I was mistaken!

[Tcubed]

The well designed full keel is quite likely the best format for still getting to windward when others can no longer.

The sheer surface area of lateral plane makes it tremendously effective at resisting leeway , even when speed can no longer be kept high.

Beware of the tremendous amount of misinformation on this topic nowadays.

[liki]

Any idea whether a suitable bell housing would be readily available for eg. the Hatz 2W35 diesel?

[JotM]

Knowledge JotM, knowledge, the two cyl. Hatz in the 10kw range are watercooled and PAR was talking about a 10hp!

I stand corrected.

[apex1]

Any idea whether a suitable bell housing would be readily available for eg. the Hatz 2W35 diesel?

SAE 6 1/2 is included.

Regards
Richard

[Claus Riepe]

I own an open 17 ft. Drascombe Driver, with a 9 hp aircooled Kubota petrol inboard engine. Very lightweight installation without gearbox, but with feathering (forward-neutral-reverse-sailing) propeller. Absolutely fabulous. If I would know how to post a photo here, I would.

P.S.
Thanks for the How-to, Apex1. It works splendidy now, I used to have problems before.
And JotM: Sorry, the Sea Raider has no inboarder -yet-. ;-)

[apex1]

I own an open 17 ft. Drascombe Driver, with a 9 hp aircooled Kubota petrol inboard engine. Very lightweight installation without gearbox, but with feathering (forward-neutral-reverse-sailing) propeller. Absolutely fabulous. If I would know how to post a photo here, I would.

Go to your post... click edit...go down to the button "go advanced"....
go down to the button "attachments" or "manage attachments"
upload.... smile!
Regards
Richard
PS auf Wunsch in Deutscher Ausfertigung!

[JotM]

Claus,

While you are at it, I would love to see pictures of your SeaRaider as well!

[Claus Riepe]

Managed to get the photos uploaded. See above.

[PAR]

Claus, Watermota no longer offers that little gadget as handy as it might seem. I've seen other similar units.

[Claus Riepe]

Claus, Watermota no longer offers that little gadget as handy as it might seem. I've seen other similar units.

PAR,
what similar units have you seen?

I thought the Watermota system is/was unique in its straightforwardness and lightweight. Being without reversing gearbox AND the ability to feather the propeller to zero drag is the key for inboard systems to be suitable for small craft. I thought there is no other system on this planet without separate reversing gearbox.

But the Watermota system was designed in the sixties, using machined bronze cast parts, which made it all expensive. Looking at it with the eyes of a value analyst, I am convinced it could be done simpler and cheaper today if done using welded stainless steel commodity parts.
But, is there really a market for such small inboard systems?

P.S.
My 9 hp installation, all included, weighs around 35 kgs. AND that weight is low down in the hull, and the propeller is in the hull centreline, all quite ideal so. Which all results in the boat also retaining good sailing properties, it BTW won the Drascombe class overall in Sail Caledonia 2006. You would have thought small sailing boats with inboarders could not do such.

[JotM]

My 9 hp installation, all included, weighs around 35 kgs. AND that weight is low down in the hull, and the propeller is in the hull centreline, all quite ideal so.

Pretty amazing! That beats many, if not most or all, 4-stroke outboards.