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Rhumbunctious
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Discussion Starter · #1 ·
A great deal of seemingly endless discussion surrounds the question of what makes a blue water or offshore cruiser, and whether some particular boat would be reasonably capable of an offshore passage or circumnavigation, the concern being how well the boat will stand up to heavy weather which can be expected to be encountered.

Apologies in advance for contributing to that seemingly endless discussion ;-)

[Caveat: I have a moderate amount of sailing experience and have survived a few storms, including ~40 knot winds and ~20 foot seas in a 22' Santana off Guam in the Phillipine Sea, and have a healthy respect for what the ocean is capable of, but I have not yet crossed any ocean (by boat) nor do I consider myself a proper "blue water sailor" -- yet, as with many members of this forum, have dreams and plans to eventually "sail around the world"... hence my ponderings on this subject]

Setting aside the frequent (and valid) observations that the suitability of any boat for any conditions depends as much upon the skill and experience of the crew, as upon the capability of the boat, and that a good sailor always keeps an eye on weather and other variables to minimize risk, I wanted to present for consideration a strategy for surviving bad weather or heavy seas in a particular type of boat designed primarily for coastal use in moderate to fair weather, but which has several characteristics which enable a possibly effective strategy for dealing with conditions far more extreme than for which the boat was designed.

In the many and varied discussions that I've followed about what makes a blue water cruiser, there is the frequent re-occurrence of several common presumptions which appear to strongly influence folks judgments and which I'm thinking may not be absolutes for all boats.

These presumptions generally concern the ability/safety of the boat functioning in heavy weather, and the potential for hardware failure from wind or water, or if rolled. It seems that many boats are rejected as suitable offshore/blue water cruisers due to the likelihood of hardware failure (de-masting, loss of steerage, etc.) or risk of sinking as a result of flooding. Namely, it is presumed that

(a) mast and rigging will be up until/unless lost by wind and/or water
(b) substantial flooding of the cabin will result in sinking, thus water tightness is critical
(c) rolling will usually result in irrepairable damage to or loss of rigging
(d) rudder and steering hardware are under continuous stress from the elements

Based on these presumptions, a blue water capable boat must have rigging, rudder, hatches, ports, etc. able to withstand the intense wind and wave energy encountered -- and therefore a boat which does not have rigging and hardware able to withstand continual use under such conditions is not a suitable blue water cruiser. Fair enough. given those presumptions, that's a logical conclusion.

But what if these presumptions are not absolutes, and that one may remove them from the equation, for a certain type of boat?

For the sake of discussion, let us consider a boat which has the following significant, and somewhat less common features:

- Water ballast and Positive hull floatation.
- Mast and rigging easily and quickly lowerable and securable to deck.
- Fully retractable foils (rudder, daggerboard/centerboard, etc).

Let us then consider the following worst case scenario, and an applied strategy for survival: Upon being faced with worstening conditions which soon will exceed the normal safe operational capabilities of the boat in question, the crew prepares the boat to ride out the weather as follows:

1. Mast and rigging is lowered and secured to deck.
2. All foils are retracted and secured.
3. Dual redundant sea anchors deployed from bow, each secured to multiple, sufficiently reinforced cleats, with chafe protection.
4. All hatches, ports, companionway, etc. secured.
5. All gear is secured in cabin in case of (or even in expectation of) rolling.
6. Exposure suits, life vests, donned by crew (or close at hand for donning quickly).

In this configuration, the rigging has minimal exposure to wind or waves, and minimal risk of loss or damage in the event of rolling as there is minimal leverage from wind/water as stowed. All foils, and thus also all steering components, etc. are removed from the stress of the elements. The boat essentially becomes a sealed container bobbing behind redundant sea anchors. Even if both sea anchors were to fail, and the boat is rolled, it should remain water tight with minimal damage. Even if a hatch or port is breached and the boat is flooded, the boat will not sink, as it has positive floatation, and risk of hypothermia is greatly reduced by the exposure suits, allowing sufficient time for the boat to be pumped out and made water tight again.

Given the high probability that such a boat, when applying the above strategy, could reasonably withstand and survive the heaviest of weather and seas which might be encountered in the open ocean, would not such a boat be reasonably considered blue water capable, to a degree, and suitable for offshore passage making, and even circumnavigation? (albeit with much greater caution and consideration of weather systems than with some other more conventional blue water capable boat).

Isn't a blue water boat thus simply a boat which is capable, in one way or another, of getting you safely and reliably across an ocean? One blue water boat may do so more quickly and comfortably (and more conventionally) than another, but getting there is what counts. Eh?

What additional variables or factors to the above strategy might render it less effective? What other forms of failure might occur which are not reasonably addressed by positive flotation, secured rigging and foils, etc?
 

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Telstar 28
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Patrick-

You're neglecting the fact that much of the roll stability of a monohull sailboat comes from the rig. By lowering the mast and lashing it to the deck, you're effectively removing this component of roll stability, which will make the boat's motion far worse for the crew as well as ultimately reducing the boat's survivability.

Dual sea anchor are also a bad idea, since they're far more likely to foul each other and then neither will work properly. IMHO, the best device for a small sailboat in survival storm conditions is a Jordan Series Drogue that is properly sized for the boat and properly anchored to the boat. This is specifically what it was designed for.

I'd also point out that much of what you're discussing-positive flotation, retractable foils, very high initial stability to prevent rolling-are all features of sea-going multihulls, be they trimarans or catamarans. The greatest danger in a survival storm is the boat sinking. Many multihulls are physically incapable of sinking, due to the materials they are made of being naturally buoyant. If you add buoyancy compartments to such a craft, they can become comfortable craft, even if flooded.
 

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What additional variables or factors to the above strategy might render it less effective? What other forms of failure might occur which are not reasonably addressed by positive flotation, secured rigging and foils, etc?
Patrick,

It's an interesting discussion. My first impression, though, is that you are making a lot of assumptions that aren't necessarily valid.

One general point that immediately strikes me is that you are advocating creating a sailboat that converts to something akin to a liferaft, in which you could weather the big storm. I'm not sure that's a desirable design objective for a sailboat, in that it would engender so many compromises on construction, sailing ability, etc. In other words, you may well survive the storm by bobbing around, but at what cost to having a decent sailing boat for the 99.9999% of the time you are not in major storms?

One specific criticism of your concept relates to the idea of striking the rig on deck when seriously bad weather is encountered. Putting aside the practical difficulties of doing this (one assumes you would not make a decision to take such a drastic measure until the weather got really bad -- in which case you would be executing the manoeuvre on a seriously pitching and heaving deck while trying to strike and lash spars, etc), the affect on the motion of the boat and its occupants needs to be considered.

Often boats that are abandoned at sea are later found afloat and intact. The decision to abandon often had more to do with the comfort of the crew -- being taxed to their limits by the boat's motion in a large seastate -- than the seaworthiness of the vessel. By striking not only the sails, but also the spars (which serve to dampen motion even with no sails bent) as you propose, the result is very likely to render the boat's motion almost unimaginably violent and abrupt. And it's hard to conceive how completely retracting the boat's underwater appendages (keel and rudder) would not further exacerbate the uncomfortable motion, with nothing to dampen roll and pitch.

Just some quick thoughts...
 

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Rhumbunctious
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Discussion Starter · #5 ·
Patrick-

You're neglecting the fact that much of the roll stability of a monohull sailboat comes from the rig. By lowering the mast and lashing it to the deck, you're effectively removing this component of roll stability, which will make the boat's motion far worse for the crew as well as ultimately reducing the boat's survivability.
Not sure I follow how removing top weight and structure that would catch wind and wave energy would result in less stability, if the boat is either bow-to or stern-to the wind (sea anchor vs. drogue). I can understand how being hove-to could provide stability, and appreciate that many motorsailors have sails primarily for stabilization rather than significant propulsion. But in the scenario where the mast is secured to the deck, don't see how that is any worse than simply being on a motor yacht of similar size. ???

Dual sea anchor are also a bad idea, since they're far more likely to foul each other and then neither will work properly. IMHO, the best device for a small sailboat in survival storm conditions is a Jordan Series Drogue that is properly sized for the boat and properly anchored to the boat.
Thanks for the pointer. Had a look at the site, very interesting and useful reading.

I'd also point out that much of what you're discussing-positive flotation, retractable foils, very high initial stability to prevent rolling-are all features of sea-going multihulls, be they trimarans or catamarans. The greatest danger in a survival storm is the boat sinking. Many multihulls are physically incapable of sinking, due to the materials they are made of being naturally buoyant. If you add buoyancy compartments to such a craft, they can become comfortable craft, even if flooded.
All true. Though the cost of a "blue water" multihull is considerably more than the class of boat I'm pondering about in this thread (so a bit "apples and oranges", really).
 

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Not sure I follow how removing top weight and structure that would catch wind and wave energy would result in less stability, if the boat is either bow-to or stern-to the wind (sea anchor vs. drogue). I can understand how being hove-to could provide stability, and appreciate that many motorsailors have sails primarily for stabilization rather than significant propulsion. But in the scenario where the mast is secured to the deck, don't see how that is any worse than simply being on a motor yacht of similar size. ???
PAtrick,

This is a concept that many people have trouble wrapping their minds around. But it is a well understood aspect of sailboat design that the rig itself, even without sails bent, has a major beneficial effect on dampening the motion of the boat. If you are skeptical, a relatively easy experiment is to drop your rig on deck, then motor your boat our into some seas or even just moderate chop. Trust me, you will be amazed at the new and uncomfortable behavior of your hull.

As for the comparison to motor yachts, it is not very apt. You are extremely unlikely to find modest or even larger sized sized motor yachts traversing oceans and weathering conditions that would not even make a well-found yet smaller sailboat flinch. Trying to design a sailboat that emulates a motorboat in bad weather is definitely the wrong approach.
 

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Telstar 28
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992 Posts
Not sure I follow how removing top weight and structure that would catch wind and wave energy would result in less stability, if the boat is either bow-to or stern-to the wind (sea anchor vs. drogue). I can understand how being hove-to could provide stability, and appreciate that many motorsailors have sails primarily for stabilization rather than significant propulsion. But in the scenario where the mast is secured to the deck, don't see how that is any worse than simply being on a motor yacht of similar size. ???
The mass of the mast and rigging is a good part of what gives a sailboat a relatively high roll inertia. By moving the mast down to the deck, you've effectively removed its effectiveness in contributing to the roll inertia, much like an ice skater when she retracts her arms... she starts to spin faster than when her arms are held out wide.

Another example: take a six foot pole with two 10 lb. weights on it. Slide the weights into the center of the pole, and try spinning the pole like a baton... it spins rather easily. Now try sliding the weights out to each end of the pole and spinning it like a baton... it takes a lot more effort to get the pole rotating now... the mass of the system hasn't changed by moving the weight, but the roll inertia of the system has changed immensely.

All true. Though the cost of a "blue water" multihull is considerably more than the class of boat I'm pondering about in this thread (so a bit "apples and oranges", really).
Smaller multihulls have made bluewater passages. Most of the monohull sailors know little of what makes a multihull seaworthy, since they don't understand the design concepts behind them. :) You'd probably be surprised with what a blue-water capable multihull can really cost if you're not into the size and luxury of a 40'+ catamaran. :)
 

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Rhumbunctious
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Discussion Starter · #8 ·
PAtrick,

This is a concept that many people have trouble wrapping their minds around. But it is a well understood aspect of sailboat design that the rig itself, even without sails bent, has a major beneficial effect on dampening the motion of the boat. If you are skeptical, a relatively easy experiment is to drop your rig on deck, then motor your boat our into some seas or even just moderate chop. Trust me, you will be amazed at the new and uncomfortable behavior of your hull.

As for the comparison to motor yachts, it is not very apt. You are extremely unlikely to find modest or even larger sized sized motor yachts traversing oceans and weathering conditions that would not even make a well-found yet smaller sailboat flinch. Trying to design a sailboat that emulates a motorboat in bad weather is definitely the wrong approach.
Point taken. I'm not looking to design a sailboat, but to consider the capabilities, with perhaps non-conventional strategies, of my current boat.

Perhaps a middle ground whereby the rigging is upgraded to the point that it is strong enough to stand the elements without sail, and left up rather than lowered.
 

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Rhumbunctious
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Discussion Starter · #9 ·
The mass of the mast and rigging is a good part of what gives a sailboat a relatively high roll inertia. By moving the mast down to the deck, you've effectively removed its effectiveness in contributing to the roll inertia, much like an ice skater when she retracts her arms... she starts to spin faster than when her arms are held out wide.

Another example: take a six foot pole with two 10 lb. weights on it. Slide the weights into the center of the pole, and try spinning the pole like a baton... it spins rather easily. Now try sliding the weights out to each end of the pole and spinning it like a baton... it takes a lot more effort to get the pole rotating now... the mass of the system hasn't changed by moving the weight, but the roll inertia of the system has changed immensely.
Right. I get it now. Thanks.

Smaller multihulls have made bluewater passages. Most of the monohull sailors know little of what makes a multihull seaworthy, since they don't understand the design concepts behind them. :) You'd probably be surprised with what a blue-water capable multihull can really cost if you're not into the size and luxury of a 40'+ catamaran. :)
I've long liked Gemini 105's, but the concensus seems to consider them too lightly built for serious circumnavigation (yes I know one was taken across the Atlantic by the builders, and that a couple circumnavigated in one, but as I recall it needed quite a substantial refit half way around, being almost worn out). Wildcats are another affordable option I've looked at seriously, but it seems that you really need to get up quite a bit more in the price range to find anything of serious durability in reasonable condition (not a major project), and that's well beyond my current means.

Positive floatation, though, remains a central feature for me, and if multihulls are excluded (however unjustly, perhaps) that narrows the range of options dramatically.

I'm looking at this as an interesting "corner case" relating to durability of the rigging. If you're going to leave the rigging up, then you simply need a certain minimal level of strength and durability, period, and that seems to be the primary factor excluding many boats from being considered "blue water". But if the strength/durability of the rigging is taken out of the equation, or at least limited only to fair to moderate weather, you suddently get a totally different game, and price bracket. The essential question is how easy/safe it is to srike the mast when/as needed. For nearly all boats, whether mono or multi-hull, that's simply not a realistic option. But there is a small number of trailerable coastal cruisers for which this scenario I've been pondering would be realistic, or at least feasible.

It's really just a thought exercise.... or probably should be ;-)
 

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Telstar 28
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992 Posts
The mast on my Telstar is very easy to raise and lower. :) The boat has a series of a-frames built into it that are designed to do just that. The largest set of the frames also acts as the lower-shrouds. :)

Check out the video of the mast-raising system at the builder's website.
 

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Rhumbunctious
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Discussion Starter · #11 ·
The mast on my Telstar is very easy to raise and lower. :) The boat has a series of a-frames built into it that are designed to do just that. The largest set of the frames also acts as the lower-shrouds. :)

...
Yes, that's the kind of ease of lowering that would be necessary in this scenario.
 

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The mast on my Telstar is very easy to raise and lower. :) The boat has a series of a-frames built into it that are designed to do just that. The largest set of the frames also acts as the lower-shrouds. :)

Check out the video of the mast-raising system at the builder's website.
But, SD, would you contemplate lowering your rig in rough conditions with a worsening approaching storm at sea???:eek:

Patrick, you raise some interesting discussion points but as pointed out by others, in the end I think physics and practicality will defeat you. Others have tried before you to make one boat do all things and none (to this point) have clearly succeeded and most end up doing none of those things particularly well.
 

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Reading your original post I got the impression you write about McGregor.
If that is the case: The first breaker hitting the deck with tens of tons of water would most likely destroy the boat.
If it is some other coastal cruiser the physics still applies.
Will the hull - deck joint hold long enough for storm to pass ?
Are the hatches strong enough ?
Is the hull strong enough?
What about the deck, the compression posts, bulkheads. ...
Will the battery stay in place or will it fly all over the boat (together with the stove, crew, drawers and floor boards ?
It is more then just flotation.
 

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Telstar 28
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No, I wouldn't. First off, the roll stability issue aside, I'd prefer to have sails to deal with worsening conditions than no sails... :)
But, SD, would you contemplate lowering your rig in rough conditions with a worsening approaching storm at sea???:eek:
 

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I step my mast on the water because i am cheep :D and have a good setup i cant imagine trying to do it bad weather


One year i thought it would be a good idea to leave the mast in my friends basement in Greenport and motor the boat back to Jamesport ,about 20 miles :confused:

It was a bit windy and had to be the worst time on a boat in my life :puke the boat normally would have loved the trip ,without the mast and some sail it was white knuckle rock & roll trip at 6 MPH;)
 

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Telstar 28
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THat's cause of the lower roll stability the boat has without the big stick.. :)
I step my mast on the water because i am cheep :D and have a good setup i cant imagine trying to do it bad weather

One year i thought it would be a good idea to leave the mast in my friends basement in Greenport and motor the boat back to Jamesport ,about 20 miles :confused:

It was a bit windy and had to be the worst time on a boat in my life :puke;) the boat normally would have loved the trip ,without the mast and some sail it was white knuckle rock & roll trip at 6 MPH
 

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Patrick, I have gone down that mental pathway too. You are effectively saying lets forget about sailing and just be a cork. The idea is appealing but sadly there are other considerations however that make it not so simple.
<O:p
A water ballast hull is most likely a light weight, probably tailorable, boat. With your mast down and no rudder or centerboard you will expect to have a lot of water on top and to be rolled. The boat is not a cork it is hollow and has a thin hull. <O:p
A blue water boat does not just have a better rudder and stronger mast. It has a much heavier hull, heavy floors often in an egg crate configuration, Heavy ports, glassed in structural beams to stiffen parts of the hull and a cockpit that will self bail in a minute. <O:p
It would be expected that your lightly built boat would be torn apart in minutes even without a rig or rudder to give the seas and wind a purchase. <O:p
<O:p
The exposure suit may give you 24 hours at most. Make sure you have made pre-arranged plans with a chase ship to be in the vicinity.<O:p
The smaller your boat is the better the chances of the cork idea to work. What we need to invent is something small, round would be good, water ballasted of course with a little cover over the top and soft sided. :( <O:p
<O:p
That being said a few Catalina 27's have sailed around the world. They modified them dramatically, replacing ports, hatches, and adding stiffening members in the hull and lots more.
I think what led you astray is all the reports of rig and rudder failures on well found boats. It is a lot easier to make and maintain a boat strong enough to not break in half than to keep the rig up. Not that a bunch of race boats haven't broken in half. The coastal day sailer will break in two with or without a rig in a serious off-shore storm.

Keep thinking and keep dreaming but be safe.:) <O:p
 

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Patrick :

There is no way you'd get the mast down on my ship even in flat calm. It is difficult enough with a crane. The mast and rig are very heavy and you will kill yourself trying.

The point about the loss of stability from dropping the mast is a good one. The mathematical term is moment of intertia. A boat with a big mast sticking up needs more sea disturbance to roll than one without. If you take the mast down, your ship will roll like a wee pig and it will exhaust you at the helm trying to hold on.

The concept of "blue water" boat is a loose one. There are no absolute rules. For me, a heavy ship is where it's at.....

Image of Loch Oich, Scotland - Photobucket - Video and Image Hosting

... as in a big sea the weight of the ship and that forgiving long keel is an advantage for me.

Others like a faster ship, with a fin keel. But fin keels in a giant sea have had their failures, and they are inherently less forgiving.

No sane person ever tries to go to weather in a giant sea. It is awful enough without trying that, so I am wary of the long distance selling points of fin keels, and their their rudders tend to be less well supported too. For me, there isn't a big sea selling point for them. I go for long keels every time. They suit me, and bigger seas.

Saildog speaks well of cats. They are wickedly fast in light airs, and they don't roll much, but they certainly can pitch. I have sailed on one of them, and the pitching was, for me, uncanny. For me, it's monohull, every time, in a big sea. A monohull will self-right too. A floatation chamber cat won't sink, but it won't self-right.

So, it's the shape of the ship, the weight of the ship, the keel of the ship, and there are lots of opinions. You need good gear and simple gear on the long hauls. Be wary of reams of electronics... seawater just murders them in a storm. Sea water is everywhere..... been there, done that.

I say what works for me. Others will counter.

.
 

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Glad I found Sailnet
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David -- Great post. And great last line.

I just wanted to say that lowering the mast will increase roll stability (tendency to go back upright), but it will decrease roll inertia, which results in a greater tendency to roll at high rates of (rotational) acceleration.
 

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Telstar 28
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David -- Great post. And great last line.

I just wanted to say that lowering the mast will increase roll stability (tendency to go back upright),
Bene505-

This is generally referred to as righting moment, not roll stability. :)
 
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