Mini Dashew FPB

Minimum to feel comfortable is a very broad range, because each individual has a different way to cope with motion and acceleration. But this type of vessel has some limits for seakeeping imposed by the hull design.
If the wave period is twice the spacing of the hulls, then the natural frequency in roll creates a resonant condition and extreme motions. Further, the cross structure is vulnerable to slamming if the wave heights are large enough. Finally, due to the relatively short hull length for the displacement, catamarans can experience significant pitch motions.

Hope that helps a bit.

Richard

 

I would again agree with Apex1, but might add a few comments as well...

When the wave period is twice the hull spacing, the technique on a catamaran is to get off that point of sail. It is a very uncomfortable ride. It will thrash you all around. Even a very small change in course will move those waves from directly abeam to slightly aft, which allows the length of the cat to soak them up and stops this motion. Sometimes, you can't avoid this problem because the smaller waves may come from your beam while the larger from your stern. Then, you have a catamaran limitation to live with. I was just talking about in another thread.

Slamming of the bridgedeck is another thing that can be avoided by technique. The cause of bridgedeck slamming is either sharp waves coming up between the hulls, or more commonly, going to windward and pushing your hulls into (and under) very steep waves. If the hulls have enough buoyancy, they will push the rest of the boat up over the chop. So, the slamming is not only a function of the cat's bridgedeck height, but also a function of the displacement available as the boat is shoved underwater by momentum. If your hulls carry enough reserve buoyancy, they will keep above the water and keep the bridgedeck clear. This is one of the main arguments for a lighter catamaran being a better catamaran. They don't plow through the head seas, they pop up and over.

Catamarans, as Richard said, experience significant pitch. There is no seamanship fix to this one, as far as I know. The only fix I'm aware of is to have a long waterline for a given "size" catamaran. Catamarans also tend to jump from hull to hull with a very quick motion. These are simply motions you either get used to (like a monohull rolling or heeling), or motions that do not work for you. You must decide for yourself if these motions are acceptable. I like these motions more than my wife does, for instance. She prefers the monohull motion, but prefers everything else about the catamaran, so we stayed with catamarans. I got more seasick and annoyed with the motion of our old monohulls. Rolling at anchor at night was the dealbreaker for me, as a permanent monohull liveaboard. I had many a sleepless night and I couldn't deal with it anymore.

Lastly, to directly answer the question, it is my opinion that a 37' cat would be about the minimum I would personally feel comfortable with crossing oceans.

 

The more I look the more I don't see what the Dashew did as amazing.
They will spend the same amount of money with a boat twice as wide, far more comfortable and nice looking.
With a separate pilothouse
Dixon Kemp, Lursen, Sander Row, Abeking and Rasmunsen, DeVries and that the only few did this kind of hull for a century. And beautiful.
Why copying something that was already copied, big, small or medium size.
I think in my eye the one who approach the most the efficient hull with elegance is Tad with is light passage-maker serie.
I know it is one of our contention with Will, we disagree on this one. I hope he forgive me
It is only my two cents
Daniel

 

Renko for a wheelchair handy boat,coastal cruiser type take a look at the Bluewater Coastal Cruisers.

Living is all on one level with rear master's stateroom-long,skinny,can go fast or cruise economically at 9 knots.
Huge deck,tons of storage.

Keeping an eye on the weather,they've done the Caribbean.

Stumble owns a 58'

As usual yachtworld will give you an idea,and very reasonably priced and gas versions are dirt cheap...

 

my thoughts exactly. Keeps the aesthetics we like, and good hulls can be had for cheap. I am reasonably competent with woodworking, so building the interior is something I can do to save costs, conceivably 1/20th of the FPB.

With the gear reduction and engine swap - what sort of prospects are there for mileage?

 

something like this sparks some ideas:

http://www.cruisingclub.org/pdfs/bws_foxy_lady.pdf

 

Greetings,

The mini FPB done by kiwifinn in the gallery is the best yet.

Peace.

 

In the UK there is a LRC58 being build!

 

Looks to me like you're just spamming the forum.............

(same post on three threads, and first posts from this "member", all pushing the same supposed product:
see http://www.boatdesign.net/forums/powerboats/tell-me-about-nordic-tug-54-a-43577-3.html#post588882 and http://www.boatdesign.net/forums/po...minum-under-200k-euro-42318-6.html#post588881 )

 

Sorry to upset you but I am new to this site and I noticed your question regarding cost. I am currently building a 58ft Aluminium Long Range Cruiser and the total hull package is about £70000.00. This includes all materials lasercut from nesting plans and then asembled and fully welded. The total displacement is 14000kg.
so depending on who you use it should be possible to buiuld your Nordic Tug (despite larger displacement) for under 200k Euroes or £160000.oo

 

Dear Jeremy
I am quite happy to introduce you tothe yard if you are realy serious in building your Nordic Tug 55!

 

Hmmm............

OK, so you're not reading the threads you're posting to, just advertising this boat, it seems to me.

If you were you'd see that some were two years old and that I'm not building a boat of this size, just commenting on three pointless posts.

You sure look like a forum spammer to me..............

 

One of the largest cost of a modern boat is "modern" interiors and outfitting.

As the boats are special in their slender L/B ratio, the hull will need to be a new build.

A rebuilt engine and tranny should be half of a new engine.

A dry stack/keel cooling industrial or truck engine and just rebuilt tranny will be about 1/5 --1/10 the cost of new.

Back in the home building days folks would create things like pilot house windows from visiting a bus place and purchasing scrap bus pax lexan
.A few bucks , a special plastic drill and a 3/4 lexan window is born , rather than a $4,000 purchased one.

Sure it wont slide and open , install another hatch.

The boat could be created to add on all the expensive lifestyle stuff LATER , if ever..

A sun cover rather than a 20KW noisemaker and multiple zone controlled air cond?

Flopper stoppers , rather than hyd system gyro ,and powered fins.

Diesel cook stove for galley and fire place in saloon , rather than thermostated central heat ?

The point is lots of sail cruising was done in the 1930's and just after WWII with mostly JUST A BOAT! , its all they had , and in the books I have read the voyagers of that era seemed content.

If its not aboard , you don't have to fix it.

If course you wont be able to lie in your bunk and have the temperature and cycle time of the Joker valve sent to your I phone . Will you miss it?

FF

 

Which is exactly what we did with Ataraxia, no nonsense, no marble counter top just decent and safe boat building

 

The trick is to build say the pilot house as IF it were going to have the big buck items like heated windows.

Use the cut out size for the hole , but cover it with bolted lexan .

Same with the hatches Goyot sized holes , but a Maurice Griffith home made hatch till......?

A set of beds for the noisemaker is cheap in a new build hull, as is a seperiate fuel tank, if someday it will be a "get home".