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Old 01-07-2004, 06:45   #1
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is there a huge difference in price between...

"coastal" and "offshore" sailboats?

whats the difference, whats the implication by the name, and whats the reason for the enormous price difference, or am I wrong?
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Old 01-07-2004, 13:26   #2
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Not so much the boat it's self, although different makes will comand different prices. But it has to do with the gear the vessel is carrying. Offshore would probably have bigger and better sail wardrobes, safety equipment, water maker, power genrating systems and so on. Of course, that isn't alway's the case either, as some sail the world with almost nothing in regards to the creature comforts. As for designs, some boats sail better than others in differing conditions. Both designs can be found in either coastal or offshore situations and thus, all price ranges can be found in both.
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Old 01-07-2004, 21:37   #3
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is a "coastal" boat limited to a certain distance / depth / water condition? Is the depth of an "off shore" boat prohibitive of it berthing in standard marinas? What draws the distinction between the two types of boat?
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Old 01-07-2004, 21:58   #4
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Perhaps light-weight and heavy-duty?

Are ya wrong?

Well, if ya been offshore in a light weight coastal cruiser in a storm, ya may see the light and appreciate the difference in cost.

Think "over-kill" regarding quality, construction and equipment.

Your coastal Hunter or O'Day may not qualify in that category, yet many of those have sailed offshore with great success.
Depends on yer nerves and experience....And faith.....
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Old 01-07-2004, 22:52   #5
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Would it be the difference in say a Toyota Rav4 vs. a Jeep ...

where they both might do it for the highway and street, the Rav4 is not going to handle itself so sure footedly in offroad conditions?

Is it weight and / or displacement that creates the difference then? overall length a factor as well? What do you consider way too small in these terms vs good enough vs what you think would be a _good_ idea.
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Old 02-07-2004, 06:01   #6
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I think that the terms 'offshore' and 'coastal' get bandied about quite freely without any real thought about what the differences are. A well made coastal cruiser should be more expensive than a dedicated offshore distance cruising boat because it needs to be more complex and actually needs more sophisticated engineering and construction than most people will accept in a dedicated offshore boat.

In a general sense, all boats are a compromise and with experience you learn which compromises make sense for your own needs and budget. Most times the difference between an optimized coastal cruiser and a dedicated offshore cruising boat is found in the collection of often subtle choices that make a boat biased toward one use or the other. A well designed and constructed coastal will often make a reasonable offshore cruising boat, while dedicated offshore cruising boats make very poor coastal cruisers.

When I think of a coastal cruiser vs. a dedicated offshore boat, there are a number attributes that I look for:

-Accommodations:
On a coastal cruiser there should be good wide berths, with enough seaberths for at least half of the crew for that night run back to make work the next day. An offshore cruiser is often handled by a smaller crew and so fewer berths and fewer seaberths are necessary. The berths on an offshore boat should be narrower and have leeboards or lee cloths. On both I am looking for a well-equipped galley but the galley needs to be larger on a coastal cruiser so that there is adequate space to prepare meals for a larger crew or a raft-up. Refrigeration is less important on a coastal cruiser although the case can be made for no refrigeration or icebox if you are going offshore.

-Cockpit:
A comfortable cockpit for lounging is very important on a coastal cruiser. It should be larger than an offshore boat to accommodate a larger number of people which is OK since pooping is less likely to occur doing coastal work.

-Deck hardware:
While gear for offshore boats need to be simple and very robust, coastal cruisers need to be able to quickly adapt to changing conditions. Greater purchase, lower friction hardware, easy to reach cockpit-lead control lines, all make for quicker and easier adjustments to the changes in wind speed and angle that occur with greater frequency. There is a big difference in the gear needed when ‘we’ll tack tomorrow or the next day vs. auto-tacking or short tacking up a creek.

-Displacement:
Offshore boats need to be heavier. They carry more stuff, period. The traditional rule of thumb was that an offshore boat needs to weigh somewhere between 2 1/2 and 5 long tons per person. A coastal cruiser can get by with less weight per crew person but generally is cruised by a larger crew. The problem that I have is that most offshore sailors and many coastal cruisers seem to start out looking for a certain length boat and then screen out the boats that are lighter than the displacement that they think that they need. This results in offshore boats and some coastal cruisers that are generally comparatively heavy for their length. There is a big price paid in motion comfort, difficulty of handling, performance and seaworthiness when too much weight is crammed into a short sailing length.

I suggest that a better way to go is to start with the displacement that makes sense for your needs and then look for a longer boat with that displacement. That will generally result in a boat that is more seaworthy, easier on the crew to sail, have a more comfortable motion, have a greater carrying capacity, have more room on board, and be faster as well. Since purchase, and maintenance costs are generally proportional to the displacement of the boat the longer boat of the same displacement will often have similar maintenance costs. Since sail area is displacement and drag dependent, the longer boat of an equal displacement will often have an easier to handle sail plan as well.

-Keel and Rudder types:
I would say unequivocally that for coastal cruising a fin keel is the right way to go here. The greater speed, lesser leeway, higher stability and ability to stand to an efficient sail plan, greater maneuverability and superior windward performance of a fin keel with spade rudder (either skeg or post hung) are invaluable for coastal work. Besides fin keels/bulb keels are much easier to un-stick in a grounding. In shallower venues a daggerboard with a bulb or a keel/centerboard is also a good way to go.

There is a less obvious choice when it comes to the keel and rudder type for offshore cruising. Many people prefer long or full keels for offshore work but to a great extent this is an anachronistic thinking that emerges from recollections of early fin-keelers. Properly engineered and designed, a fin keel can be a better choice for offshore work. There is the rub. Few fin keelers in the size and price range that you are considering are engineered and designed for dedicated offshore cruising.

-Ground tackle:
Good ground tackle and rode-handling gear is important for both types but all-chain rodes and massive hurricane proof anchors are not generally required for coastal cruising.

-Sailplan:
At least on the US East Coast, (where I sail and so am most familiar with) light air performance and the ability to change gears is important for a coastal cruiser. It means more sailing time vs. motoring time and the ability to adjust to the 'if you don't like the weather, wait a minute' which is typical of East Coast or Great Lakes sailing. If you are going to gunkhole under sail, maneuverability is important. Windward and off wind performance is also important.

With all of that in mind I would suggest that a fractional sloop rig with a generous standing sail plan, non- or minimally overlapping jibs, and an easy to use backstay adjuster is ideal. This combination is easy to tack and trim and change gears on. I would want two-line slab reefing for quick, on the fly, reefing. I would want an easy to deploy spinnaker as well.

-Speed:
I think that speed is especially important to coastal cruising. To me speed relates to range and range relates to more diverse opportunities. To explain, with speed comes a greater range that is comfortable to sail in a given day. In the sailing venues that I have typically sailed in, being able to sail farther in a day means a lot more places that can be reached under sail without flogging the crew or running the engine. When coastal cruising speed also relates to being able to duck in somewhere when things get dicey.

-Ventilation:
Good ventilation is very critical to both types. Operable ports, hatches, dorades are very important. While offshore, small openings are structurally a good idea, for coastal work this is less of an issue.

-Visibility and a comfortable helm station:
Coastal boats are more likely to be hand steered in the more frequently changing conditions, and higher traffic found in coastal cruising and are more likely to have greater traffic to deal with as well. A comfortable helm position and good visibility is critical. Offshore, protection of the crew becomes more important.

Storage and Tankage:
There is a perception that coastal cruisers so not need storage. I disagree with that. Coastal cruisers need different kinds of storage than an offshore boat but not necessarily less storage. Good storage is needed to accommodate the larger crowds that are more likely to cruise on a short trip. Good water and holding tankage is important because people use water more liberally inshore assuming a nearby fill up, but with a larger crew this takes a toll quickly. Holding tanks are not needed offshore but they are being inspected with greater frequency in crowded harbors and there are few things worse than cruising with a full holding tank and no way to empty it. Offshore boats generally need larger fuel tanks.


Respectfully,
Jeff
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Old 02-07-2004, 06:17   #7
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Thanks, that answered a lot of my questions...

and created many more, but I bet you expected that
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Old 04-07-2004, 08:55   #8
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Jeff and fugi: Jeff thanks for the info on sailing gaffed rigged schooners. We decided to stay with our cutter. fugi: When we purschased our boat we loooked at severa l ratios to help out.
1. displacement/lenght: a ratio of 150 and up indacates off shore.
2. Lenght/beam: a ratio of 2.7 or higher indicates offshore.
3. Beam/depth: a ratio of 4.0 indicates offshore.
4. sail area/displacement: about 15 or lower showes offshore.
a high sail area displacement ratio means more horsepower for acceleration but more sail handling. A lower sail area displacement ratio is easier for shorthanded crews in changing conditions. The sail plan is important as to where you are sailing. The last thing we looked at was the accomodations. But that is another story.
Hope this help a little. Jeff's info is very important stuff. Get all the books on sailing you can and read.
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Old 04-07-2004, 15:20   #9
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I guess I should have added, it depends on what "Coastal" implies. Here in NZ and some parts of Australia, we have some of the worse sea conditions in the world around our Coasts. Apart from deep in the Southern ocean, going off shore in NZ can often mean better seas. The number of stories we get to hear from overseas people, that the they had a great trip across the pacific only to have the worst leg of the journey approaching the Cook straight, is all too common. And the many stories we all hear of the strectch of coast at the bottom of Australia through Bass straight.
So any yacht suited to Coastal sailing in NZ is often well designed and the seperation between offshore and coastal is usually in the safety equipment carried.
Light duty yachts in NZ are often relegated to Harbour or lake sailing.
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Old 05-07-2004, 07:29   #10
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I would have a couple minor nitpick's with Tauras's post. A Sail Area/Displacement ratio of 15 is tiny, even for an offshore boat. Traditionally offshore designs had SA/D ratios in a range around 18 or so and were dependent on either large genoas, spinnakers and other kites when they hit the lighter stuff or else motoring. This low ratio also comes from the comparatively low stability in comparason to its displacement and drag that is generally typical of more traditional designs.

Depending on the rig and hull design, more modern offshore boats will often have a SA/D approaching 20 to 22 giving good light air performance without resorting to a large sail inventory or motoring.

I also think that a beam to depth ratio of 4 is excessive. That would put a 10 foot draft in a 40 foot boat when a draft of 6.5 feet or so is perfectly adequate for reasonable offshore sailing ability on a 40 footer.

Similarly a beam to length of 2.7 is a very beamy boat for going offshore once youy get over about 30 feet. Ratios over 3 or even 3.2 are not especially slim. Except in a small boat under 30 or so feet, a boat with ratio approaching 2.7 would not go to weather well, would have a small angle of positive stability, and would have a miserable motion.

Respectfully,
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Old 26-08-2004, 03:18   #11
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Ratios etc

Understanding the Numbers - Basic design formulas for sailboats
by
Roger Marshall

http://www.boats.com/

In the preliminary design stage many designers use some basic formulas to help them evaluate the boat they are designing. These formulas indicate general trends only and are refined as soon as the design is entered into the computer and a performance prediction is made. However, these numbers are still useful for the average boat buyer or boat owner to use to evaluate boats.

The Displacement/Length Ratio

According to Froude's Law, a boat with a long waterline will sail faster than a boat with a short waterline. That is why a-60 footer will go faster than a 20-footer. On the other hand, a boat with heavy displacement is slower than a boat with a light displacement. This is why a 50,000-pound 50-footer is slower than a 10,000-pound 50-footer on certain points of sail. (In general, a heavier boat is faster upwind in heavy air than a lighter boat because waves slow the lighter boat.)

A designer marries the length and the displacement by using the displacement/length ratio, which states that the displacement in tons divided by a fraction of the waterline length cubed equals a certain number. Written out, the formula is:

(Displacement in pounds/2240) / (LWL/100)3

This number is said to give an idea of the ability of the boat. In general, boats with a displacement/length ratio of under 70 can get on a plane in the right conditions. Most production boats have a ratio of 125 to 250. Boats that have a ratio over 250 tend to be cruisers. Long-distance cruisers may have a ratio over 300 and often up as high as 400, although a boat with that high a displacement/length ratio would be very slow in lighter winds. In order for the displacement/length ratio to give a good idea of any trends, a graph should be made by plotting displacement/length ratio against sail area.

Froude's Law

Froude's Law also states that a displacement hulled boat will go faster than the wave length created by the hull as it moves through the water. This wave length is equal to 1.34 x LWL. In other words, a boat with a 25-foot waterline length will go no faster than 6.7 knots. Most boats can be overpowered or may sail down the back of a wave and temporarily exceed this calculated maximum, but they cannot maintain that speed unless they have a low displacement/length ratio when they plane.

The Sail Area to Displacement Ratio

This formula indicates how much sail area is available to push each pound of displacement through the water. It is non-dimensional in that sail area, which is in square feet, divided by the displacement divided by 64 to get the volume of displacement raised to the 2/3 power. This reduces the volume of displacement to a squared power so we divide sail area in square feet by another squared number. The formula reads:

Sail area (square feet) / (Displacement/64)2/3

It may also be written as:

Sail area / (Disp/64) .666

The sail area to displacement ratio generally works out to be between 14 and 30, with the highest numbers being the fastest boats in lighter winds. Boats with a high number also tend to accelerate faster and need to be reefed earlier. I generally plot this ratio against waterline length to get a graph that appears to be meaningful. If you wish, you could plot it against LOA + LWL/2 to average the overall and the waterline lengths of a boat.

Ballast Ratio

As an indicator of stability in modern boats this number is close to useless unless the hull and keel shapes are close to identical. However, it is useful when you are making a cost comparison of several boats. When used in this manner it gives you an idea of the amount of ballast a boat carries relative to the other materials in the boat. The ratio is:

Ballast x 100 / Displacement
Wetted Surface to Sail Area Ratio

Another formula that gives fairly good results is the wetted surface area to sail area ratio. This formula tells you how much wetted surface a boat has relative to its sail area. A boat with a lot of wetted surface is likely to be slow in light winds when sailed against a boat with low wetted surface. (In fact, in winds under 8 to 10 knots this is probably the most important ratio of all.) It is simply:

Sail area in square feet / Wetted surface area in square feet

Typically this ratio is around 2 to 6, with the lower number indicating that a boat has a lot of wetted surface relative to its sail area. A boat with a low number will be a slow light-air boat. The only drawback to this formula is that you will have a hard time getting the wetted surface ratio from the designer or builder.

Beam to Length Ratio

The beam to length ratio compares a boat's beam against its length. It serves as an indication of whether one boat is beamier than another for its overall length. For the average user this formula gives an idea of the amount of interior volume a boat has relative to another vessel. The beam to length ratio can be made up in several ways. I prefer to use the following formula:

(LWL + LOA/2) / Max beam

Typically this number is around 5 for a 12-meter boat and may be as low as 2.5 or 3 for fatter hull shapes. The higher the number the better the boat's stability should be and the better the boat's windward ability.

Capsize Formula

The capsize formula, which was developed in the aftermath of the Fastnet storm in the Irish Sea indicates a boat's tendency to capsize. Boats with a value of under 2 are less likely to capsize than boats with a higher value. The ratio is calculated:

Beam / (Displacement 1/3 /64)

This ratio assumes that beamy boats are harder to capsize and harder to re-right and that heavier boats are also harder to capsize. Remember that this formula is only an indicator not a hard and fast rule.

Fuel to Displacement Ratio

How much fuel should a boat carry? If the boat has a generator it will require more fuel than a boat with no genset. If it is a cruising boat it will typically carry a lot more fuel. I developed a formula to compare the fuel capacity of various boats. It is:

(Fuel in gallons x 7.5 (changes gallons to pounds) x 100) / Displacement

I found that boats with a fuel/displacement ratio of under 1 percent tend to be racers and do not require a lot of fuel. Boats with a ratio of 5 to 7 percent tend to be long-distance cruisers. Most production cruisers that do not go far from shore have a ratio in the 2 to 4 percent range.

Fresh Water to Displacement Ratio

This ratio has a similar function to the fuel/displacement ratio, in that it indicates how much water a boat should carry. A long-distance cruiser without a watermaker has a ratio of over 5 percent, while a racing boat often has a ratio under 1%. Production cruisers tend to be around 3 to 5 percent. A boat with a watermaker may have a value as low as 2 percent. The formula is:

(Fresh water in gallons x 8 (changes gallons to pounds) x 100) / Displacement

Prismatic Coefficient

The prismatic coefficient gives the designer an idea how full or thin the underwater part of the middle of the boat is relative to the ends. For example, a square-ended barge where the ends of the boat are identical to the midsection has a prismatic coefficient of 1. A sailboat has a prismatic of about half of that number because the ends of the boat are tapered. The number is typically about .51 for a boat intended to be fast in light winds and can be up to .59 for a boat intended to be fast in heavier winds. Unfortunately, it is impossible to calculate this value from numbers given on a brochure. You need to ask the designer what it is.

The coefficient is found by taking the largest transverse area of the hull and multiplying that area by the waterline length. This gives you a box shaped like the largest midship section. The volume of this odd-shaped box is divided into the volume of displacement of the hull. The formula reads:

(Volume of displacement) / Largest sectional area x LWL
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