[Search for users] [Overall Top Noters] [List of all Conferences] [Download this site]

Conference unifix::sailing

Title:SAILING
Notice:Please read Note 2.* before participating in this conference
Moderator:UNIFIX::BERENS
Created:Wed Jul 01 1992
Last Modified:Mon Jun 02 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:2299
Total number of notes:20724

1046.0. "Finding your vessels limit..." by OURVAX::NICOLAZZO (Better living through chemistry) Tue Nov 15 1988 13:50

     How do poeple determain the capabilities of their vessel (short
    of trial and error? (the trial part is ok, but the error part bothers
    me a bit:-) I would think that few people on the water know a whole 
    bunch about naval architecture or the manufacturing methods of their 
    boat (At least i know i don't).
    
     I know that a lot depends on the skipper and crews capabilities,
    ie; a good skipper and crew could safely survive a storm in a lesser
    boat then an inexperienced crew could survive in a better boat.
    But you hear so much about knowing the limits of your vessel I was
    wondering if there were some criteria people look for. Such as,
    if the vessel is X it can handle Y. Or is reputation of the manufacturer
    a big factor? 
    
     As an example, i own a Watkins 27'. If she fell off a 10' wave
    would she be likely to break apart? Would it take a 20' wave?
    Would a 30Knt blow be risky? Or would it take 50Knts? I not looking
    for answer to these specific questions but, see what i'm getting
    at?
                       
     Again, i'm sure there are a million variables and no real rules
    but i bet there's lots of opinions:-)

T.RTitleUserPersonal
Name
DateLines
1046.1"I don't want to find it"PBA::SCHLEGELTue Nov 15 1988 20:0814
    Very simply: Boats are made for what they are to be used for. If
    someone is  planning to use a boat in 10 foot or 20 foot slab-sided
    waves, then he should have the experience and boat for these
    conditions. (Read the experiences of the racers in the Fastnet
    race a few years back.  The boats were BIG but the conditions were
    still too much).
    So the prudent sailor does not go out in those conditions. I think
    what you are asking, is what happens if I am caught out there? 
    The answer is "either your boat can take it or it can't" What the
    hell are you going to do at that point but pray a lot.  Hopefully,
    anyone caught in those conditions has the necessary experience.
     
                        

1046.2Boat & crew capabilitiesCDR::SPENCERJohn SpencerWed Nov 16 1988 15:1125
Knowledge and experience are both important.  Knowing your boat's 
construction (strength and features) and the properties of each critical 
component will help you assess the likelihood of damage from falling off a 
10' wave, for example.  You might use this understanding in deciding
whether to fight your way to safe harbor or give up and run with it.  

Your experience with the boat can tell you how she handles various
sub-ultimate conditions.  Extrapolate that data to make some informed 
predictions about worse conditions.  For instance, will she foot to
windward while pitching wildly?  Some boats will, some won't.  This is the
other part of knowing what the boat can take. 

The trickier part, for most people without much experience, is knowing 
what the crew can take.  It's most difficult to truly judge the situation 
when the serious stress is on; humans very often over- or underestimate
their capabilities.  Either can be dangerous. 

Others have said it, but I'll repeat it:  Till you're more confident, 
stick to conditions you understand and trust.  Besides adding to your 
reflexive knowledge, even in trying to avoid trouble, it has a a way of 
finding all of us sometimes.  Those are the times when your knowledge and 
experience will be disproportionately extended.

J.

1046.3It comes with timeAKOV12::DJOHNSTONWed Nov 16 1988 16:1110
    In almost case, a vessel' ability to weather nasty conditions for
    a short period of time exceeds that of the crew.  Trouble will find
    you, as John says, and it is true that each time it does and you
    make it through you've learned a little more.  However, common sense
    is assumed here.  The boat's basic construction can be judged by
    a good marine surveyor as to how much punishment it will stand.
    Don't push it.
    
    Dave

1046.4MSCSSE::BERENSAlan BerensWed Nov 16 1988 21:0837
The precise limits of a boat's capabilities simply aren't knowable --
one cannot say with certainty that a boat will survive falling off a 20'
wave and not survive falling off a 21' wave or that a boat is capable of
sailing in 40 knot winds and not capable of sailing in 45 knot winds.
Knowing the precise limits does not much matter, I think, since sea and
wind conditions are both extremely variable and uncontrollable. It is
accurate to say, I think, that there is a wind and sea that will sink
any boat. 

The general capabilities of a boat are knowable, and these capabilities
depend on the design and construction of the boat and the capabilities
of the crew. Knowing the general limits of a boat's capabilities allows
one to minimize the chances of having to survive wind and sea conditions
near or past the limits of a boat's and crew's capabilities. Absurd
examples of this are obvious and easy -- I wouldn't dream of sailing a
J-24 to Bermuda though I remember hearing of someone looking for a crew
to deliver a J-24 to Bermuda. 

Every boat, regardless of what the builder claims, is more suitable for 
some sailing conditions and less suitable for others. Read enough, look 
at enough boats, and talk to enough people and eventually you will be 
able to form a rough idea of what conditions a particular boat will 
survive without damage to boat or crew.

A couple of caveats here. The forces of wind and water at sea do not
lessen to accomodate the boat. The current design trends favor light,
fast boats because they are supposedly easier and more fun to sail. But
light construction, even with the use of exotic, expensive, high
strength materials means less overall strength than heavier construction
using the same materials. The strength of a beam in bending increases
with the cube of its thickness, so, very, very roughly, doubling the
thickness of a hull doubles its weight and multiplies its strength by 8.

Second, simply because someone has sailed a particular boat to somewhere 
and back does not make the boat suitable for the passage. That someone 
may simply have been very lucky. 

1046.5At what level of risk are you comfortable?MIST::HAYSCan't go back and you can't stand still ... Phil Hays ZSO1"Fri Nov 18 1988 21:4924
RE:.4 by MSCSSE::BERENS "Alan Berens"

> Simply because someone has sailed a particular boat to somewhere and back 
> does not make the boat suitable for the passage. That someone may simply 
> have been very lucky. 

There is another factor here as well,  and that is the level of risk that
one finds acceptable.  If one knows in advance (and of course one never
really does) that there is a two percent chance of dying on a voyage with
a given boat,  is that an acceptable risk?  I would say no,  at least at
this point in my life.

On the average,  for every person who stands on top of Mt. Everest,  about 
one person dies in the climbing team.  Is this an acceptable risk?

Mt.  Rainier has a rate of a little less than one death for every thousand
people who climb it.  Is this an acceptable risk?

That someone has sailed a particular boat to somewhere tells you something
about the level of risk they can accept.


Phil

1046.6Insurance CompaniesECADSR::FINNERTYFri Dec 30 1988 20:5215
    
       re: trial and "error"
    
       I'd expect that insurance companies would have a complete list
    of "errors", i.e. of sea disasters of the kind you mentioned.  
    Perhaps they could be pursuaded to release this information to you
    in the name of promoting boating safety.
    
       Rather than looking at the most daring voyage a particular boat
    survived, I'd be much more interested in finding out about the
    least daring voyages which particular boats did *not* survive!
    
       - Jim (Irish Mist)
    

1046.7Not a long trip...DECWET::HAYSCan't go back and you can't stand still ... Phil Hays ZSO1"Fri Dec 30 1988 22:2212
RE:.6 by ECADSR::FINNERTY

> Rather than looking at the most daring voyage a particular boat survived, 
> I'd be much more interested in finding out about the least daring voyages
> which particular boats did *not* survive! 

I would guess that every common boat type has at least one sunk at it's
moorings.


Phil

1046.8FASTNET FORCE 10VIA::RUDYSat Jan 07 1989 12:5623
    I highly recommend you read FASTNET FORCE 10 by John Rousmaniere.
    This is the story of the Fastnet race of 1979 when the race was
    hit with Force 10 winds in the Irish Sea.  Given the local it was
    much more difficult for crews then ocean swells but rather confused
    seas.
    
    	A summary of boats in that race
    APPROX   STARTERS	FINISHERS RETIRED  CREWS ABANDONED	SUNK
    SIZE				   LOST	  AND
    						  RECOVERED
    
    55-70	14	13	   1	    0	    0		 0
    44-55	56	36	   19	    0	    1		 0
    39-43	53	23	   30	    0	    0		 0
    34-38	64	6	   52	    6	    4		 2
    33		58	6	   44	    6	    7		 1
    28-32	58	1	   48	    3	    7		 2
    
    TOTAL	303	85	   194	    15	    19	         5
                                               
    
    	This doesn't tell the whole story of course.  

1046.9GRAMPS::WCLARKWalt ClarkSun Jan 08 1989 15:2111
    >>  This doesnt tell the whole story of course.
    
    Yeah, like the fact that the big boats missed the brunt of the storm
    because they were further along the course when the storm swept
    in.   The boats that got hit with the worst of the storm were
    in the middle and at the back of the fleet (smaller boats naturally).
    
    This doesnt tell the whole story of course (either).
    
    Walt 

1046.10an optimistic viewMSCSSE::BERENSAlan BerensMon Jan 09 1989 14:1911
re .8:

The table also says something about what size boat might be too small 
for ocean sailing.

On the other hand, the table is also very encouraging for those of us 
that sail smallish boats on the ocean. The conditions encountered in the 
Fastnet storm were truly appalling (and probably worse than most sailors 
ever encounter), but only 3 of 116 boats 33 feet or less in length were 
actually sunk. 

1046.11CHEFS::GOUGHPPete Gough @REO 830-6603Mon Jan 09 1989 14:425
    Equipment and materials have also improved greatly since the '79
    race.
    
    pete

1046.12Sea conditions rather than wind.POBOX::DBERRYMon Apr 30 1990 19:2119
    I hear a great deal of discussions about wind force as a big factor. 
    The greatest factor in races like Fastnet is the sea conditions
    encountered.  I have been in 28 ft. boats in 55 knots.  The sea
    conditions did not correspond to what one would expect with those wind
    forces, they were flat by comparison.  I have done more heavy weather
    stuff than the average Joe, and sea conditions are what I worry about
    most, and they don't always go hand in hand.  Most people have done
    sailing in relatively sheltered waters where the sea conditions neve
    get real bad.  Be careful of real sea conditions based on experiences
    on sheltered waters.  You might want to drop two notches on the
    Beaufort scale for a more realistic comparison.  The greatest factor in
    safety is the skill of the skipper and crew.  You should expose
    yourself to increasing conditions through time to build your skill and
    confidence, just don't over do it.  An experienced skipper and crew
    might well have a great time in 45-50 knots( I know I have), where an
    inexperienced crew might hate life at 20 knots.
    
    							Dave Berry