ideal ocean crossing trawler yacht

Murray I'm sorry,
So many words to read I flashed over the quote marks. Take it as a compliment. I'd be flattered if someone thought something I wrote was actually said by a NA .. especially TAD.

But to TAD's credit most existing twin engined trawlers are very much less efficient than single engined trawlers. But a twin engined boat of the same displacement and powered w the same amount of power (as in hp) w all other elements of design being about the same little if any difference will be found. That's my opinion but TAD's opinion carries MUCH more weight than mine. But real comparable boats are almost impossible to find.

Eric, go back to post 2 and click on the Watson 72 link. Then look for the 58' project they are working on and look up its propulsion options, Watson offers 3 options for all its boats. Option 3 is twin engines half the size of the single and they are showing as 60.5% efficient as opposed to the single being about 55% efficient.

I actually thought about our conversations last night while I was reading those specs.

CPseudonym said:

Eric, go back to post 2 and click on the Watson 72 link. Then look for the 58' project they are working on and look up its propulsion options, Watson offers 3 options for all its boats. Option 3 is twin engines half the size of the single and they are showing as 60.5% efficient as opposed to the single being about 55% efficient.

I actually thought about our conversations last night while I was reading those specs.

Click to expand...

Craig, you are suffering from 4'-itis. It is the W54 Project. But thanks for highlighting the article. Quite informative.

What I don't like about the W72 is the 3m draft. Hell, even with 1.5m draft I have found myself touching bottom in the south end of Moreton Bay the last couple of times I have been out. Now I know that the OP is talking about crossing oceans, but if you are in tropical waters at either end of the journey then a 3m draft just isn't going to cut it.

Craig,
Thank you much. The Watson site is very good reading, informative and about the most objective presentation of design and marketing from a single source.

It will take me more time to take away what's availible from the Watson site. I'll be interested to see if they use ballast and how much. And to read their thoughts on seaworthyness.

Thanks for pointing this out Craig as I may have missed it otherwise. I frequently pass over these guru-like sources that are most often full of self worship.

You're welcome Eric. I found it interesting that he would prefer a 6:1 transmission but cannot buy except slightly under 5:1 without the expense of custom built.

Sorry for the confusion there Brian, but what's 4 feet amongst friends?

Is there anyone who does engineering spaces better than Pacific Motor Yachts nee Watson? This one is of the 72..

This one the 48..



Having spent many years on ships with propulsion plants from HP steam to diesels, to gas turbines these are simply art. Well designed, noteworthy access, planned for maintenance and replacement as required.

It's clear they are building small ships vice some of the many alternatives.


PS - I think this may have be hashed over in a very similar thread several years ago. Not surprisingly, it appears to be reaching a similar conclusion.

Ok, I'm going to limit my answer here to trawler type boats and brands often discussed here. Fleming would be my first choice in the under 100' range. A Fleming 65 would be good, but a 78 better.

I'd consider something from the Cheoy Lee Serenity line to be worthy. The 68' or the 90'.

Nordhavn 78 or 86'.

I think of steel as the more logical material, but don't think of any particularly ocean transiting steel boats under 100'. I would want something proven so that eliminates boats like the larger Bering's and the Seahorse Super Duck.

You don't find the various Dashew FPB's particularly appealing in the range?

While a definitely niche design, they are certainly developing a significant user base with great reviews and of course the Dashew's have decades of ocean cruising experience to apply in their design process.

In my military mind, cost being no object, it would be tough to improve on their design philosophy and execution with Circa.

Here's the latest. I think this at 78ft is reaching the "no crew" limit personally.....









http://www.setsail.com/fpb-78-the-dream-machine-new/

The link for the whole story...

MRRiley said:

You don't find the various Dashew FPB's particularly appealing in the range?

While a definitely niche design, they are certainly developing a significant user base with great reviews and of course the Dashew's have decades of ocean cruising experience to apply in their design process.

In my military mind, cost being no object, it would be tough to improve on their design philosophy and execution with Circa.

Here's the latest. I think this at 78ft is reaching the "no crew" limit personally.....

SetSail » Blog Archive » FPB 78: The Dream Machine

The link for the whole story...

Click to expand...

I think the problem with the Dashew hull is that its a sailboat shape; fat in the middle and slim at both ends.....this of course produces massive pitching in a head sea as the hull rotates around the all that volume midships, and the thin bow/stern plunge up and down like a seesaw.....

"I think the problem with the Dashew hull is that its a sailboat shape; fat in the middle and slim at both ends.....this of course produces massive pitching in a head sea as the hull rotates around the all that volume midships, and the thin bow/stern plunge up and down like a seesaw.."

Perhaps if the D boats were ferro cement , at 15lbs Sq Ft of hull

but with modern construction I believe they will simply rise up on the wave , not pitch into it.

Esp if moving fast.

FF said:

"I think the problem with the Dashew hull is that its a sailboat shape; fat in the middle and slim at both ends.....this of course produces massive pitching in a head sea as the hull rotates around the all that volume midships, and the thin bow/stern plunge up and down like a seesaw.."

Perhaps if the D boats were ferro cement , at 15lbs Sq Ft of hull

but with modern construction I believe they will simply rise up on the wave , not pitch into it.

Esp if moving fast.

Click to expand...

There was a video of a dashew 64 off NZ in head seas pitching wildly, but it seems to have been taken down off YouTube.

Ill try and find the test in MBM which also highlighted the problem ....

One more boat worth considering is the Kiwi Artnautica Yacht Design 58.
You can buy it built or plans.Not as good as a Dashew however a bit more real world in pricing.Supposed to be very efficient.
I'm a bit of a fan of the naked alloy look.

Seems there is a lot of guessing in this thread and lots of I think in here. Lol and that is good too.

Now then how about some of you with experience crossing oceans speak out as well. Shh I did not just say anything against any one in here.

See we are looking at the big glass boats such as krogen, nordhavn and such AND also steel such as bering and so forth.

Thinking about lots of North travel such as the inside passage with lots of Alaska and north and Canada and places like new Zealand and green land and so forth and other destinations.

Want to carry 2 tenders. Bigger fishing one and smaller 13 or 14 foot rib. Steel hulls can answer to this where glass is always limited unless you jump I to 68 and up and then it depends on the build.

Strictly power and no sale and a wide beam with twins which will run off individual power and fuel supply.

This will be home for us.
Thanks
Jim

Ah - just remembered, this is the boat I'd really like to have for ocean crossings. Video below of its performance. Also - I think this type of video dispells the notion that these long thin boats have more pitch than the short/fat houseboats like the Nordhavn. They cut through the waves.

Ocean Eagle 43



https://cmn-group.com/products-and-services/military-vessels/tsm/ocean-eagle-43/

LRC58Fan said:

Ah - just remembered, this is the boat I'd really like to have for ocean crossings. Video below of its performance. Also - I think this type of video dispells the notion that these long thin boats have more pitch than the short/fat houseboats like the Nordhavn. They cut through the waves.

Ocean Eagle 43

https://cmn-group.com/products-and-services/military-vessels/tsm/ocean-eagle-43/

Click to expand...

Video seems impressive. How to tie to dock??? Covered berth width???

LRC,
Terribly wet of course but pitch wise she runs nicely.

One very odd thing is that the amas sheer slopes down like the main hull. On the main hull it makes sense but one would think a designer would want the amas to lift smartly and get their support struts up and out of the solid water. Speaking of the ama support struts they are beveled down on the leading edge and for lift I would think they should be beveled up. I would think the amas digging in would tend to slow the boat significantly and yaw/steer it to one side. In a severe case the ama could in theory even roll the main hull. just seems bass awkwards to me.

Multi hulls seem good even in videos but I've never seen vidio of one in big seas like 15' or 25'.

Fish Catcher Jim, only thing keeping you looking at nearly 70'+ boats is your tender requirements. Throw those out and either a KK42 or N46 would fit the bill. It would probably be cheaper to buy a 17' center console at every port of call and throw it away when you leave than to carry two across oceans on your deck.

Either way it's not a bad problem to have.

How about a offshore trawler cat design; 55' ,15kts cruise on twin 500hp....

B34 Ocean Cat - Mooney Boats Ireland

Fish Catcher Jim said:

Seems there is a lot of guessing in this thread and lots of I think in here. Lol and that is good too.

Now then how about some of you with experience crossing oceans speak out as well. Shh I did not just say anything against any one in here.

Click to expand...

It might seem like there should be a definitive answer but much depends on what you want and how you want to do it. Personally I've crossed the Pacific at least 7 times, the Indian 6 so I can certainly claim to have much afloat experience. The qualifier is of course the ships I was on range from 433 to 866 ft and 4,300 to 48,000 tons. A darn site bigger than what you're looking at I'd expect.

Reading the design philosophy sections of the Dashew and Watson sites will provide quite a lot of insight as to the why. Length limits apply in terms of crew requirements and in some locations, navigation requirements including pilotage. Obviously to a point, bigger is better, but many crossings have been made on much more modest vessels.

Fuel requirements, electrical generation and distribution, water, cold storage and your demand for amenities will shape your search. As you address those, I think you'll find exactly what you are looking for in terms of a transoceanic cruiser.

Looking forward to seeing what you come with! Happy hunting!

manyboats said:

LRC,
Terribly wet of course but pitch wise she runs nicely.

One very odd thing is that the amas sheer slopes down like the main hull. On the main hull it makes sense but one would think a designer would want the amas to lift smartly and get their support struts up and out of the solid water. Speaking of the ama support struts they are beveled down on the leading edge and for lift I would think they should be beveled up. I would think the amas digging in would tend to slow the boat significantly and yaw/steer it to one side. In a severe case the ama could in theory even roll the main hull. just seems bass awkwards to me.

Multi hulls seem good even in videos but I've never seen vidio of one in big seas like 15' or 25'.

Click to expand...

I agree with all your points. The bevel downwards doesn't seem to make much sense, but I suspect Nigel Irens knows a little more about this type of boat design than I do. Perhaps it helps keep the boat more planted on the water in very rough seas.

And in really rough seas - yes, multihulls may be a concern because if they ever go over sideways, you know they'll never be "self-righting".

Interesting - just checked the Nigel Irens web site and he has a number of new yacht designs... based on this same approach - see below:






Source:

Home Page - Nigel Irens Design

Since we are talking about ocean crossers, what do y'all think about the Buehler Duck 382. It's actually a 41' boat I think. Supposed to be an ocean crosser.

Would that pitch badly being so short? My 36 LWL does but it's a diff hull shape and shorter.

manyboats said:

Murray wrote;
"Why twin engines? Unquestionably, a bigger engine with a single large-diameter propeller would be more efficient."

I don't think it's "unquestionable" A case can be made for either but objectivity is scarce on this question. I'm just questioning the "unquestionable" position on this issue and wish no further comment or thread hijacking. There's lots in the archives but most is very slanted. My point is that IMO twin or single is probably not an issue or even close to a must have of either choice.

Click to expand...

I think my use of "unquestionable" should be questioned....

If you can get propeller speed down to 450-500 RPM, the diameter becomes less of an issue. As Pacific Motorboats shows. The Watson 54 is a large, heavy displacement, massive boat. It has lots of depth inside for the big drop 5:1 reduction gears. But let's look at reality in a PL48 which is what I was writing about. A single 5:1 gear on centerline with straight shaft would be possible. Twin engines with vee-drives and 5:1 reduction will not happen with stock equipment. The best you will do is 3:1 reduction, and so the larger diameter single will be more efficient. With a 3:1 reduction(shaft speed 833rpm) the twin engine Watson 54 will have a Bp of 36.3, far less efficent than the single engine version with 5:1 red.

MRRiley said:

Fuel requirements, electrical generation and distribution, water, cold storage and your demand for amenities will shape your search.

Click to expand...

That sums it up quite smartly

Ed Gillet's need for amenities were small on his 'solo voyage' to Hawaii, so a 21 foot sea kayak was good enough;

San Diegan's 63-Day Odyssey : Solo Kayak Paddler Makes It to Hawaii - latimes

I would also add that ego sometimes plays a part in the size of some peoples vessels...

MRRiley said:

Fuel requirements, electrical generation and distribution, water, cold storage and your demand for amenities will shape your search. !

Click to expand...

Wifey B: I'll take a box of amenities please. I love them. So tasty.

Afraid my ocean boat has to be fast, carry lots of fuel, have huge freezers, make it's own water (well with help from the ocean) have many generators and engines, have washers and dryers and have amenities. I know. I'm greedy. Want it all. Has to be bigger for me as hubby answered on another forum. Still at under 100', I'll go with Fleming too. But the bigger one.

I 've never seen the hull on a Fleming. It looks like a relatively flat bottomed hard chine boat w perhaps less deadrise than a Classic GB. Not the ideal hull for serious offshore cruising. Am I wrong? What is the Fleming hull like?

There must be something between a Watson and a Fleming.

manyboats said:

I 've never seen the hull on a Fleming. It looks like a relatively flat bottomed hard chine boat w perhaps less deadrise than a Classic GB. Not the ideal hull for serious offshore cruising. Am I wrong? What is the Fleming hull like?

There must be something between a Watson and a Fleming.

Click to expand...

You're wrong about Fleming for serious offshore cruising. Just read some of Tony Fleming's blog and he's been everywhere in a 65'. As to design, I quote below:

"The Fleming hull is a semi-displacement design with moderate deadrise, a fine entry forward and a hard-chined, modified V aft - all adding up to a yacht optimized for running most efficiently at 9 to 10 knots, but which can also cruise comfortably at up to 18 knots. A long keel provides directional stability as well as protection of the running gear. The generous flare of the bow and soft forward sections contribute to a comfortable, dry ride especially at passagemaking speeds. The hard chines not only provide lift at higher speeds, but they have an added benefit of creating a more stable boat when at anchor or at the dock."

BandB,
The Fleming is obviously a good boat and can go offshore but it is far from ideal. People do it all the time but light, shallow and fairly flat bottom boats belong close to shore. How close? ... Depends on the boat and the water. And when you need conditions to that question that type of boat is not the "Ideal Ocean Crossing Trawler Yacht". This thread title is not made of the right words. Ocean crossing is a job for Passagemakers not trawlers. But if you're going to take off accros an ocean aboard a trawler it should be done w a more "ideal" hull than a Fleming. A KK 42 for example.

manyboats said:

BandB,
The Fleming is obviously a good boat and can go offshore but it is far from ideal. People do it all the time but light, shallow and fairly flat bottom boats belong close to shore. How close? ... Depends on the boat and the water. And when you need conditions to that question that type of boat is not the "Ideal Ocean Crossing Trawler Yacht". This thread title is not made of the right words. Ocean crossing is a job for Passagemakers not trawlers. But if you're going to take off accros an ocean aboard a trawler it should be done w a more "ideal" hull than a Fleming. A KK 42 for example.

Click to expand...

I would choose to cross in a Fleming 65 or 78 over a KK 42 any day and that is not a slam against the KK 42. Now, I personally wouldn't choose to cross in either. Still, I know enough about Fleming and it's proven passagemaking to feel comfortable. So you can have your ideal and I'll have mine.

My actual ideal would be a 164' Westport.

If you just wanted to get across the ocean on a boat book passage on a freighter. If you want to get across an ocean on your own boat, with your own set of limitations, any of the boats youz guyz are enamored with ( Watson ?) is probly not what your gonna be on. Lets get real. Lets talk about open ocean boats that most of us can afford.

manyboats said:

BandB,
The Fleming is obviously a good boat and can go offshore but it is far from ideal. People do it all the time but light, shallow and fairly flat bottom boats belong close to shore. How close? ... Depends on the boat and the water. And when you need conditions to that question that type of boat is not the "Ideal Ocean Crossing Trawler Yacht". This thread title is not made of the right words. Ocean crossing is a job for Passagemakers not trawlers. But if you're going to take off accros an ocean aboard a trawler it should be done w a more "ideal" hull than a Fleming. A KK 42 for example.

Click to expand...

Eric

Unless I read your implications incorrectly; I believe you look through a glass darkly, to an extent, regarding sea-kindly hull designs available for ocean crossing "small" yachts.

You consistently imply how you feel hard chines, on any portion of a hull, makes for poor handing in wind/storm disruptive seas. I believe that hull designs incorporating forms/shapes of both round bilge displacement type and hard chine planning effects in different hull sections can be excellent for small yacht handling in sea conditions... short of hurricane fed, breaking waves above 30' tall.

Properly mixed hull design I just stated IMO would in general be applicable to boats in the below 100' dimension. Boats larger than that become a weight mass that alters bad weather handling capabilities. Big Ships are a completely different item... in that their deep draft, wll, and enormous weight shifts the entire paradigm for handling in disruptive deep sea conditions.

Art