Blue Water

[thomm225]

Originally Posted by Glenn.Brooks

One interesting thing to me is to look at the boats that have been entered in the single handed Transpac, Transpac, and Vic Maui Races over the years. These boat lists will give you a good idea of what constitutes a proven "blue water" sailboat, versus a coastal cruiser.

Really?

You mean like a Hobie 33?

Merit 25?

Moore 24?

Olson 30?

Cal 20?

All these boat have completed the SHTP but I don't think I'd want to cruise "Blue Water" on one of them.

I'm thinking my coastal cruiser would be better......

[Steadman Uhlich]

Originally Posted by FV Black Pearl

Markwesti, I looked at link, very surprising.... I would have thought a blue water boat would be at least 35 feet, they are mostly smaller than that. I also was told by broker(agent) once not to buy the Gemini 105... but its listed there. I didn't see a Hunter in list heard many things about them...alot unfavorable.

JPA Cate....I couldn't find the post you mentioned, I did a search but nothing from that in tittle or author....so not sure which post.

I have been deep sea fishing many times, some good weather some bad. Im not unsure about moving to the sea, Im not unsure about staying on the boat for months at the time. My uncertainty comes from buying the right boat. Trawlers are limited in distance, motor running all day long...I leaning away from that. A hunter or other production boat would be (to me) limited same as trawler. Thats why I feel I need a blue water boat...Im not headed straight out to sea but I see it in my future. I don't see selling this one and buying another in 5-10 yrs.

Blue Water Boat TOPIC Threads as of June 2017 (many hours of reading)
https://cse.google.com/cse?cx=011403...ter&gsc.page=1

Cheeki Rafiki (Keel falls off, All Hands Lost)
https://cse.google.com/cse?cx=011403...iki&gsc.page=1


Blue Pearl (rudder mount on bulkhead fails, boat fills with water, boat abandoned)
https://cse.google.com/cse?cx=011403...earl&gsc.sort=

Wauquiez (quality boat brand)
http://www.cruisersforum.com/forums/...ir-164093.html

Bestevaer 49 (high end custom boat)
http://www.cruisersforum.com/forums/...st-147499.html

Hope that helps.

[Cheechako]

Bluewater= offshore conditions

[markwesti]

I hear you S/V Black Pearl , blue water boat at least 35'... I think so . People do things in small boats , doesn't mean it's right or wrong it depends on the person . However I don't think anyone here is going to argue with the fact that water line equals a good thing it's just a question of how much water line can you afford . Also I'm a long keel guy but that is just me , there are others that don't like long keels because they are not associated with speed or pointing , but the plain fact is in a rough seaway they work , I'm not saying others don't . I would like to ask a few questions and make a few pointers ... First is it just you on the boat ? Plan to live aboard for multiple yrs. at a time ? How much stuff do you need on the boat for yourself are you a minimalist , of course You need stores but on the other hand if you are anchored in paradise Safeway might be only a dink ride away . Our little boat carries 100 gals. water and over that in dry storage and 36 gals. fuel not to mention lockers for clothes and stuff . Most boats that are advertised as blue water have storage capacity and more important a good DWL that's displacement to waterline length ratio . Here is a bolg. that I think you will find informative because these two did what you are kind of talking about , sadly they are done and sold the boat at a big loss . Sundowner Sails Again | No Longer Lubbers

[FV Black Pearl]

Markwesti,

I plan to do this, my last girlfriend did not...she is history. Im going to keep putting one foot in front of the other until Im on my boat...maybe alone, maybe not. I wouldn't say Im minimalist I like gadgets and creature comforts...but I won't be needing almost anything I own now so that helps... I most likely will live aboard year round however I do contract work when possible, usually 2 week stint and a lot of times its in Europe. I did it steady in 2015, 6 months in 2016, 2 months so far this year. I have been getting my house ready to put on market this year so haven't traveled out of country since january.
Im not planning on staying in marinas, Id like to stay on the hook or mooring ball when I arrive at a destination. I like my internet but I don't upload much and don't require it so I don't think it will be an issue. AC/heat and generator Im thinking is a must, I don't want it all the time but sometimes you need it. I have been shopping for 40 foot range boats but beginning to think that may be more than I need.
Ive seen Sundowner videos, and Delos, La vagabond, SSL, and one of my favorites...Sailboat Story. My biggest inspiration is Untie the lines (White Spot Pirate) I started watching her when she first started...the boat was awful at first...I know a lot of times she just wanted to cry...but she didn't she kept on and went sailing... although she's stuck in Panama or somewhere right now waiting on a new motor...lol.

[JPA Cate]

[QUOTE=FV Black Pearl;2407887]

JPA Cate....I couldn't find the post you mentioned, I did a search but nothing from that in tittle or author....so not sure which post.

/QUOTE]

Hi, Black Pearl, Use the "Search" button at the top right of the page, go down to the Google Custom Search, and it will take you there. The Google Custom Search is a different search engine from the regular CF one, and when you don't have the exact name or title, it works much easier. However, I went back and looked them up for you.

"Cheeki Rafiki Loss Report": http://www.cruisersforum.com/forums/...-145354-9.html

Keel sump repair: http://www.cruisersforum.com/f55/kee...ir-164093.html

The Blue Pearl Sinking: http://www.cruisersforum.com/forums/...ng-129942.html

I hope these help.

Ann

[JPA Cate]

Black Pearl,

One time we met a family from New Zealand, they had been dairy farmers, and he welded up his own steel motor vessel. It was about 65 ft, iirc. It had room for two small motorcycles in the forward hold. It was constructed around its tankage. They wanted to put in some fuel in NZ, but not top it up, and then go to Australia where fuel was less expensive and could be purchased duty free, and fill it there. Next fill was Indonesia, the Abu Dubai, and then, Panama (!!!), and then home to NZ. They were gone 10 yrs. or so, a couple and their 13 yr. old son, at the time. The engine was a slow turning, dead reliable, 2nd hand Gardiner diesel, and they just did the whole thing!

I guess what I'm getting at in my slow way, is that you might find it interesting to ask a similar question on the Motor Vessel forum. While it is true that you can spend a lot of money these days on diesel fuel, good quality sails are very expensive, too, berthing fees are a factor, and also a minimum of 3rd party insurance.

Here's the link on the thread about the Bestevaer 49: http://www.cruisersforum.com/forums/...st-147499.html

Another issue is singlehanding. Time for another, search, man.

Ann

[FV Black Pearl]

JPA Cate,
That is a nice boat for sure!
Ive looked a lot at single handling and most boats Ive looked at said they were capable... But I probably won't be doing much of that under sail. Hopefully when I get boat and to coast Ill meet some great like minded folks to hang out with and maybe even a first mate. Im 5 hours from the coast here and nobody here dreams about sailing...in fact most just dream about retiring and mowing their lawn and sit on porch...thats how you grow old. Im headed to the beach first mate or not.

[Auspicious]

Originally Posted by markwesti

Most boats that are advertised as blue water have storage capacity and more important a good DWL that's displacement to waterline length ratio.

In naval architecture DWL is the length of the design waterline.

Displacement to length ratio is Δ/L. You have to be very careful of units. It's an empirical measure and so tonnes/ft and MT/m are quite different.

You have to be careful using metrics as most of the empirical measures date from a time when hulls were all pretty much the same. Scaling is nonlinear so you can't compare LT/ft to lbs/ft just by multiplying by 2240.

[StuM]

Originally Posted by Auspicious

In naval architecture DWL is the length of the design waterline.

Displacement to length ratio is Δ/L. You have to be very careful of units. It's an empirical measure and so tonnes/ft and MT/m are quite different.

You have to be careful using metrics as most of the empirical measures date from a time when hulls were all pretty much the same. Scaling is nonlinear so you can't compare LT/ft to lbs/ft just by multiplying by 2240.

Also frequently referred to as DLR (Displacement Length Ratio).

You are correct that it's not linear. It's not just calculated as Displacement/Length. You can calculate it using the standard formula in lbs just by dividing by 2240.

The reason it is not linear is because it is actually calculated on displacement and the cube of the length:

DLR = Displacement / (LWL * 0.01)³ where Displacement is in long tons and LWL is in feet.

which is exactly equivalent to:

DLR = (Displacement / 2240) / (LWL * 0.01)³ where Displacement in lbs and LWL is in feet.

And if you want to go metric, you get exactly the same result with

DLR = (Displacement /1016.05) / (LWL * 0.003048)³ where Displacement is in kilograms and LWL is in metres.


Added: Since Displacement is in effect a cubic linear measurement and we are dividing it by another cubic linear measurement, the resultant figure is non-dimensional. IOW, it is just a "number" without units. It doesn't matter what units you use to measure it, the number will be the same as long as you use the appropriate factors. (You could measure the boat's displacement in firkins and the length in furlongs - with the appropriate factors, you will still come up with the same Ratio).


BTW, I think you meant imperial, not empirical )

[ranger58sb]

Originally Posted by FV Black Pearl

I say if and when because several years ago when I decided to go in this direction I just assumed I would buy a trawler....I know power boats so it made sense.

You may find it useful to look at trawlerforum.com (sister site).

The analogous terminology more often used over there would probably be "passagemaker" as contrasted with coastal or inland boats of various design (sorta like blue, green, brown water, respectively).

-Chris

[Auspicious]

Originally Posted by StuM

Also frequently referred to as DLR (Displacement Length Ratio).

Only because many people can't be bothered to figure out how to put Δ in a computer document or post. *grin*

Originally Posted by StuM

It's not just calculated as Displacement/Length. You can calculate it using the standard formula in lbs just by dividing by 2240.

It isn't nondimensional. Look at the units.

I did mean empirical. Data was gathered over centuries on performance and plotted and curves were drawn through scatter plots. As recently as the late 70s when I went to Webb we understood that measured data is only applicable when the conditions are the same. When looking at a ratio and (worse) things like "comfort ratio" you must understand what is being measured and if what you are comparing the measurement to is relevant.

[StuM]

Originally Posted by Auspicious

It isn't nondimensional. Look at the units.

It IS non-dimensional.

Displacement is a measure of the volume of water displaced by the vessels mass i.e. cubic feet. (Expressed in tons as a result of multiplying the cubic feet displaced by the weight of a cubic foot of water)

When you cube the LWL you also get cubic feet.

So you are dividing cubic feet by cubic feet. When your numerator and denominator are the same units, the result must be dimensionless.

I did mean empirical. Data was gathered over centuries on performance and plotted and curves were drawn through scatter plots. As recently as the late 70s when I went to Webb we understood that measured data is only applicable when the conditions are the same. When looking at a ratio and (worse) things like "comfort ratio" you must understand what is being measured and if what you are comparing the measurement to is relevant.

My apologies. I see what you mean, You confused me with the use of metrics and empirical in the same sentence. Now I see that you meant "metric" as in "measurement", not as in "SI units"

[Auspicious]

Originally Posted by StuM

It IS non-dimensional.

Tonnes/cu ft is not non-dimensional which is the classical measure of displacement to length ratio. Volume (cu ft)/cu ft is non-dimensional. Some folks use that but it is not as common. The literature is mostly tonnes/cu ft.

And yes, you got my application of metric as a measure and not an SI unit. I'll be more careful with my vocabulary in future. *grin*

[StuM]

Originally Posted by Auspicious

Tonnes/cu ft is not non-dimensional which is the classical measure of displacement to length ratio. Volume (cu ft)/cu ft is non-dimensional. Some folks use that but it is not as common. The literature is mostly tonnes/cu ft.

Tonnes of sea water displaced = cubic feet of sea water displaced x 35 (a non-dimensional unit)!

Here's a few references that a quick Google turned up:

Comparing Design Ratios - Sail Magazine
"Displacement-Length Ratio (D/L) is a nondimensional expression of how heavy a boat is relative to its waterline length."

Ted Brewer Yacht Design
"The D/L ratio is a non-dimensional figure derived from the displacement in tons (of 2240 lbs) divided by .01 LWL cubed, "

Sailboat Ratio Information
"This is probably the commonest of these measures, and indicates whether a particular boat is "heavy" (eg a cruising design) or "light" (eg a racing design) for its length. Because it is "non-dimensional" (achieved using a cube of waterline length) this ratio can be used to compare boats regardless of their length and the resulting ratios can be categorized as follows:"


Note: It's called the vessel's "displacement". Not its "weight" for a reason.