lighter, faster...safer?

[jakmedic]

Does this sound right?

Just had a discussion with a Jboat guy who cruised the world for a year in a J40, with lots of time "offshore". I asked him if he didn't think it might have been safer or maybe more comfortable during the offshore parts and heavy weather in a heavier cruiser, say a vagabond or other similarly known "bluewater" type boat (I'm in dream-planning stages and seeking lots of advice). His feeling was that it's much safer to be in a light, quick boat like his J (displacement 19k lbs) that moves easily, even in strong winds offshore, even in seas and weather. He claims to never need to reef in up to 30 knots even with 100% gen and full main both out, given the narrow hull, strong righting moment and ability to translate wind force into forward motion (rather than heel) of his J. Says he tends to blow past the heavier displacement boats who are usually double reefed and hard to handle in strong wind, while he's got 2 fingers on the wheel, full canvas and still fully in control and comfortable.

I'm just learning this stuff, and I've never really been offshore, but my instinct tells me that all other things being equal (which I know they never are), a heavier, more solidly built cruiser (ie Formosa, vagabond, Passport, etc) is going to keep you more comfortable and safer in a sea or a blow. That's why they call them cruisers, right? If I ever make my plans happen, I expect to do mostly coastal stuff, but also hope to spend time to and from the Caribbean, with my wife and little one on board, so safety and comfort are going to be important considerations. Just wondering if this fellow's claims sound way off or not...

[Jeff_H]

Boats like the Vagabonds represent designs that evolved from the best thinking of the 19th century commercial sailing vessels but a vast amount has been learned in the century or so since the time when these designs made sense. Comparatively speaking these boats are hard to handle, uncomfortable, and slow, offering minimal advantage in terms of motion comfort over the better modern offshore cruisers.

The better modern offshore boats like the newer Hylas's and Hallberg Rasseys are boats that are intended to be able to stand up to the abuses of offshore work while offering increased ease of handling, seaworthiness and more seakindly motions.

Another way to look at its this, is to size a boat by its displacement. In other words, first pick the displacement that you need, then choose the length. For the most part, within reason, if you chose between two boats of equal displacement, one perhaps 20-25% longer than the other, especially if the longer boat had a proportionately longer waterline, the longer boat of the same weight would be more seaworthy, seakindly, have a greater carrying capacity, be easier to handle and have a similar purchase price and maintenance cost to the shorter boat of an equal displacement.

So while the 32,000 lb Formosa 41 is very heavy and reasonably seaworthy for a 41 footer, a 28,000 lb Hylas 46 or a 33000 lb Hylas 54 would make a much better choice for offshore work in almost all ways.

By the same token, the 17,000 lb J-40, while not as robust as a 17000 lb Westsail 32, the J-40 would be an easier boat to sail across the normal windrange and would offer a nicer motion in most conditions.

For the record, while the J-40 was a great design for its day and an excellent coastal cruiser, I would not think it is all that great even with modifications as a dedicated offshore cruiser. In the 20 plus years since the J-40 was designed hullforms, vertical center of gravities, and sail plans have further improved.
Respectfully,
Jeff

[jakmedic]

Jeff H:

Thanks for your reply. Ok, I got that of two boats with the same displacement, a longer hull/waterline makes for a better sea motion and sailing characteristics, and that's useful info. Sorry if I'm outing myself as a dolt here, as I think you may have just explained this, but does it then follow that of two boats with the same length waterline, the lighter boat will (generally) sail more favorably (esp "offshore" and in weather)? I know it will be quicker, but won't it require a lot more work to keep under control? Be harder to keep upright? Be thrown around by the seas? Is it really an advantage to be nimble in rougher conditions, or (given the same length boat) do you want to be heavier?

[Stillraining]

The j boats made the Guru's list this year.

[jakmedic]

Who's the Guru? I wanna read his thoughts on the J....

[Ilenart]

jak,

fairly sure Stillr is talking about this list

http://www.sailnet.com/forums/buying...ry-2008-a.html

On your original question of heavier, vs lighter boats, I don't think there is one right answer. Many people prefer lighter boats for the reasons that the Jboat guy mentions. Just as many prefer heavier boats as they state better sea kindliness, less motion in a seaway, easy to heave-to, etc. Some of the claims a contradictory so I think you need to gain a bit of experience to decide what you prefer. Light vs heavy is also just one characteristic; just as important is size, budget, intended use, your level of experience, etc, etc.

I started in the "heavier is best" league (my boat weighs 30,000lbs / 14,000kg), however I can see the virtues of a lighter boat, as Jeff's post details. Still all the boats that I like (in the 40-50ft range) are all medium / heavy boats, so my guess is my next boat will probably be similar to my current boat.

Ilenart

[camaraderie]

I would note that while some J boats are listed...the J40 is absent...reflecting agreement with JeffH's comments.
Personally...I really don't like the really heavy and plodding hull designs in some heavy displacement boats evn though they may be stable and comfortable at sea. Not do I like the really lightweight approach or think that it is wise to trade speed for safety or seakindliness. To me...going to a fully cored hull, a deep fin keel or a spade rudder just to make the boat go faster are poor choices in a boat designed and intended for long distance cruising. I have a moderate fin and protected skeg myself but I'd rather be in a full keel beast than the other extreme even if it takes a day or two longer on passage.

[Jeff_H]

Jakmedic; "I'm outing myself as a dolt here.......does it then follow that of two boats with the same length waterline, the lighter boat will (generally) sail more favorably (esp "offshore" and in weather)? I know it will be quicker, but won't it require a lot more work to keep under control? Be harder to keep upright? Be thrown around by the seas? Is it really an advantage to be nimble in rougher conditions, or (given the same length boat) do you want to be heavier?"

Jakmedic, With all due respect, I would not feel at all like a dolt. These are not cut and dry questions and the answers will vary widely from design to design. It can be very hard to wrap your mind around many of these complex and seemingly contradictory types of yacht design concepts.

To try to discuss a few of your points, when you talk about ease of handling, as a general rule, and within moderate proportions, the heavier the boat, the larger the sail plan and the more physical strength that it takes to sail. But that has little to do with ease of keeping a boat under control. Control is a matter of design. It is more about the ballance of the sailplan to hull, the shape of the boat's hull when heeled and vertical and the design of the underwater foils (keel and rudder).

When you talk about light boats vs heavy boats; their seaworthiness, motion comfort and so on have less to do with their weight than their design. Weight in and of itself does nothing good for a boat; it does not make it stronger, more stable, more seaworthy, or give it a more seakindly motion or larger carrying capacity. It just makes it heavier.

To one degree or another, given a moderately low amount of form stability, the most critical factors in terms of motion comfort and stability will be the vertical center of gravity, the roll and pitch moments of inertia, with dampening being the secondary factor in motion comfort. Very often heavy boats (especially the traditionally design Asian built boats) carry much of their weight in interior furnishings, teak decks, heavy spars and rigging and have a deep vertical center of bouyancy. This makes for a boat that does not offer a whole lot of stability relative to its drag and sail plan, and tends to roll and pitch excessively as compared to a more moderate design.

If you are really trying to understand stability as it relates to ease of handling and storm survival in the real world, the relationship of a boat's drag to its stability becomes very important. Seakeeping requires that a boat be able to sail and be controlled in all but the most extreme conditions. As a boat's drag goes up, so does its need to carry more sail area for any given condition. Moderate displacement boats with moderately easily driven hullforms can get by with proportionately less sail area in a blow than a more traditional high drag hullform. When you consider the case of many of the fiberglass traditional boats, they often have comparatively small ballast to weight ratio's carried in comparatively shallow keels and so do not have an abundance of stability, and yet since they need to carry more sail area than a more moderate design, they end up being pushed to a point where their lack of stability relative to their drag becomes comparatively more a liability.


On the other hand, if that boat's relatively heavy weight comes in the form of a high ballast ratio, with the ballast located at the bottom of a deep keel then obviously the heavier boat will have greater stability than the lighter one. A good example of that might be the J-44 or J-130 as compared more extreme 43-44 foot boats of a similar length, say a Beneteau Oceanis 43 or some of the Asian built 'Garden like' traditional cruisers. As another point of comparason, one of my favorite long distance cruising boats is the Kelly Peterson 44/46's. While these are similar in length to the Hardens and Vagabonds, the Peterson's more easily driven hull form and longer waterline lengths should make them a much better boat offshore.

The reality is, if you are going offshore, moderation in design is the best way to go. There is little to be gained by going for the extreme light end of the spectrum, nor is there any gain to going toward the extreme heavy ends of the spectrum. But in the middle there are a lot of good choices that would serve you well across the wide range of conditions that distance cruising implies.

Lunch is done so I need to get back to work......
Respectfully,
Jeff

[sander06]

I think it's rather amusing to look at the new "cruising" yachts in Cruising World magazine. A lot of them have fin keels, spade rudders, duel steering and a little piss-ant saildrive. Of course, the main cabin is as spacious as my living room with as many handholds. If these space-age boats are your cup of tea... go for it. Personally, I think they're a joke!!

[CharlieCobra]

Agreed. After going to bad weather on Oh Joy who's cabin top I can reach across, I wouldn't wanna be caught out on a condo in the piss. I like not being thrown 17' across empty space to slam against something hard.