Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 05-06-2015, 17:42   #16
Registered User
 
Muckle Flugga's Avatar

Join Date: Apr 2008
Location: Aboard the Ocean wave
Boat: 55' sloop.
Posts: 1,426
Re: Offshore novice question

Quote:
Originally Posted by roverhi View Post
The worst part heaving to is it leaves the boat sideways to the waves. That leaves the boat subject to being rolled by the not so mythical 'Rogue Wave'. If conditions aren't too bad, you need a break and/or you don't want lose any hard gained ground against the storm, heaving to is an option. If you are in a major storm where you could be hit by a breaking wave, running off dragging a drogue or wharps to slow the boat down is a better way to go. Of course that requires sea room to run off into. You won't be making a lot of way because of the drogue or whatever but it sill will be a few knots to leeward. When planning a passage, plan to stay as far offshore as possible till you need to make a landfall.

You really do want to practice heaving to in at least strong wind situations to see how the boat will behave.
I may be misunderstanding you, or you may be doing it wrong, but a correct heave to attitude does not leave the boat beam on to the prevailing seas. It actually leaves the boat in a position not unlike that of a boat actively forereaching. The angle to the wind and prevailing seas should be between 30 and 60 degrees. The higher the angle, the better the heave to. On my own boat I OFTEN use a heave to to lie off until daybreak if making landfall in poorly charted waters, or to wait for some system or other to move out of the way before continuing. It works absolutely fine in often quite violent seas, and I was once hove to for some 3 days between NZ and Fiji because of weather both North and South and plenty in between. Perfectly comfortable, I got through most of a box set of Breaking Bad. My craft is 30 tons modified semilong keel and heaves to under main alone, barberhauled to windward, with a small scrap of riding sail on the backstay to keep her nose into it more consistently. She rides beautifully.

Each technique of storm defense requires its own skills and practise, and carries its own inherent dangers. I would say there is a hierarchy. What destroys a boat is the sudden realisation of the potential energy inherent in the kinetic differential between boat and water. Forereaching, heaving to lying to a sea anchor all carry the advantage of reducing the overall velocity of the boat vis a vis the water, therefore reducing the potential energy of a disastrous roll or similar (bear in mind water in waves is actually moving in a circular fashion). Running with no drogues is for a strongly crewed boat only with skilled helmsmen on short watches. It tires the crew and places the boat in extreme danger of broach, roll, capsize and pitchpole, not to mention conferring an entirely false sense of the actual conditions, which will in fact be worse than they are perceived to be. Forereaching also requires skilled helms and strong numerous crew, but has far less danger of truly severe consequences in a broach or similar. Running under drogue is nice in theory, but it is often hard to tune the drogue adequately to the wavetrain, and you may end up with a constantly snatching rig. It will also require strong crew and careful helming as it is not a "leave alone" strategy. Lying to a sea anchor is, in the right boat, a superb strategy, but few have actually adequately practised it, and many boats do not so ride well at all. One indication for how your boat may behave in this circumstance is observation of how it behaves actually on anchor. If it tends to sail against the anchor in a strong yawing motion, then sea anchor is likely to be a poor option. Etc etc.

So the hierarchy? First, passive techniques, starting with the easiest, which is a good heave to. Second passive techniques with mechanical assist, so lying to a sea anchor. If that is or becomes untenable, then active forereaching if practicable with crew and boat. If not, then move downrange under drogue or similar. Only as a last resort run freely. Doing so will keep you in bad weather for longer, exhaust your crew, stress your boat, and likely broach, roll, knockdown, dismast and/or pitchpole. Running free is a last resort, though may also be the ONLY option if you have a lightly built pizza wedge. The latter surf better etc. but are far more vulnerable to nose diving and pitchpoling, as their forward buoyancy is massively overpowered by that of the aftersections.

Remember, if you heave to, you can prepare the boat for sea anchor, you can begin to actively forereach under engine or sail or a combination, and you can turn and run under drogue or free if you so decide. If you are running free before a big storm… you are already at your last option.

About heaving to, though, I am surprised to hear so many here who seem to doubt its usefulness. Of course as I said above, not all boats (or skippers) do it well, but if yours does, then it is a genuinely invaluable technique, particularly for short handed cruising boats. Those who say it "invites disaster" examples please?

Although I would not lie ahull as does the boatman, he is quite correct to say that most attempt to heave to with far too much foresail. Indeed, many who think they can do it at all, don't seem to fully understand its most basic principles.
__________________

__________________
‘Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance.’
Muckle Flugga is offline   Reply With Quote
Old 05-06-2015, 17:56   #17
Registered User

Join Date: Sep 2012
Posts: 4,960
Re: Offshore novice question

Quote:
Originally Posted by monte View Post
Heaving to works well on our cat. About 1/4 jib backwinded, helm lashed hard to windward puts it at about 20 degrees to the wind so easy enough to approach the waves on a good angle. Fore reaches at about 2kn in 40kn wind, probably technically fore reaching rather than being hove to, but comfortable enough.
I'm still trying to figure out how you can hold a position that high on the winds?? What is going on with a Cat that allows it to forereach so high compared to a mono??
__________________

__________________
robert sailor is offline   Reply With Quote
Old 05-06-2015, 17:59   #18
Registered User
 
Muckle Flugga's Avatar

Join Date: Apr 2008
Location: Aboard the Ocean wave
Boat: 55' sloop.
Posts: 1,426
Re: Offshore novice question

Quote:
Originally Posted by monte View Post
Heaving to works well on our cat. About 1/4 jib backwinded, helm lashed hard to windward puts it at about 20 degrees to the wind so easy enough to approach the waves on a good angle. Fore reaches at about 2kn in 40kn wind, probably technically fore reaching rather than being hove to, but comfortable enough.
Good to know. Thanks. As Robert Sailor asks, though, it is an extraordinarily high angle. I would almost suggest possibly too high as you surely risk getting knocked back through the wind?
__________________
‘Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance.’
Muckle Flugga is offline   Reply With Quote
Old 05-06-2015, 18:03   #19
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,369
Re: Offshore novice question

The wind isn't a problem heaving to.... the water is.
You're right "a correct heave to attitude leaves the boat forereaching...." etc
Unfortunately when green water is going OVER your boat, as well as pushing the bow, it changes everything... it's much heavier than the wind pressure... and throws your bow down off the wind and on it's beam. The water pressure spins the bow off the wind around the CLR.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 05-06-2015, 18:14   #20
Registered User
 
Muckle Flugga's Avatar

Join Date: Apr 2008
Location: Aboard the Ocean wave
Boat: 55' sloop.
Posts: 1,426
Re: Offshore novice question

Quote:
Originally Posted by Cheechako View Post
The wind isn't a problem heaving to.... the water is.
You're right "a correct heave to attitude leaves the boat forereaching...." etc
Unfortunately when green water is going OVER your boat, as well as pushing the bow, it changes everything... it's much heavier than the wind pressure... and throws your bow down off the wind and on it's beam. The water pressure spins the bow off the wind around the CLR.
Dissipating its energy in the process. It will lie abeam only briefly, quickly regaining its bow to attitude. And, for the record, a correctly hove to vessel should not forereach. It should slip downrange in its own slick. This is hard to achieve, but not impossible. It is why I use no heasail, barberhaul my main, and have a riding sail on the backstay. In those three days I moved around 60 miles downrange. That's it.

Meanwhile, on a run, the boat will constantly be in danger of a violent broach with far higher energy, leaving it not merely beam on, but with enough boat speed to cause the keel to act as a lever and knock her down, or capsize and roll. Believe me I've been there. In a storm your boat is simply GOING to be swept from time to time. The question is what happens at that point, and immediately afterwards.
__________________
‘Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance.’
Muckle Flugga is offline   Reply With Quote
Old 05-06-2015, 18:40   #21
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 6,389
Re: Offshore novice question

Quote:
Originally Posted by Muckle Flugga View Post

About heaving to, though, I am surprised to hear so many here who seem to doubt its usefulness. Of course as I said above, not all boats (or skippers) do it well, but if yours does, then it is a genuinely invaluable technique, particularly for short handed cruising boats. Those who say it "invites disaster" examples please?

Although I would not lie ahull as does the boatman, he is quite correct to say that most attempt to heave to with far too much foresail. Indeed, many who think they can do it at all, don't seem to fully understand its most basic principles.
That was a fantastic and well written post. Thanks.

I, too, am surprised. But from everything I've read on this and other boating forums, altogether too many people don't practice it and when they do they're using huge genoas. Wrong, wrong, wrong.

Like docking, it takes practice. And also going out when it's snotty and NOT nice. How else will you know what your boat can do?

Thanks again.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 05-06-2015, 18:47   #22
Eternal Member
 
monte's Avatar

Cruisers Forum Supporter

Join Date: Jul 2011
Location: Australia
Boat: Lagoon 400
Posts: 3,650
Images: 1
Re: Offshore novice question

Robert, the jib backed is probably around 20 degrees more to windward than when it's sheeted normally, and the idea is to have minimal force on the jib. Enough to keep it filled and slightly driving forward, but not enough that it will be too powered up. I guess for different boats/sail configurations and conditions the angle changes a lot. Actual course over ground would be closer to 50 - 70 degrees probably, but the point is to keep the angle of approach to the waves around 20 - 30 degrees for safety and comfort. Too little speed risks falling backward on the waves and rudders, too little angle causes slamming off the wave, too big angle risks taking too much force on the beam or possibly sliding sideways on a wave. Too much speed adds unnecessary additional force. Usually one tack will be better than the other with regards to wave angle.
__________________
monte is offline   Reply With Quote
Old 05-06-2015, 18:59   #23
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,369
Re: Offshore novice question

Quote:
Originally Posted by Muckle Flugga View Post
Dissipating its energy in the process. It will lie abeam only briefly, quickly regaining its bow to attitude. And, for the record, a correctly hove to vessel should not forereach. It should slip downrange in its own slick. This is hard to achieve, but not impossible. It is why I use no heasail, barberhaul my main, and have a riding sail on the backstay. In those three days I moved around 60 miles downrange. That's it.

Meanwhile, on a run, the boat will constantly be in danger of a violent broach with far higher energy, leaving it not merely beam on, but with enough boat speed to cause the keel to act as a lever and knock her down, or capsize and roll. Believe me I've been there. In a storm your boat is simply GOING to be swept from time to time. The question is what happens at that point, and immediately afterwards.
Yeah, everyone has to work out their method. I have found conditions where it will not work at all and is downright dangerous. Main only. But I didn't try a sail on the back stay! Boat would only fore reach less than 1-1.5 knots, but still turned down and knocked on beam every minute or so.
I thought Heaving to was a piece of cake until the first time I had those sea conditions.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 05-06-2015, 19:00   #24
Senior Cruiser
 
roverhi's Avatar

Cruisers Forum Supporter

Join Date: Aug 2005
Location: Kona, Hawaii, Carlsbad, CA
Boat: 1969 Pearson 35 #108 & 1976 Sabre 28
Posts: 6,006
Send a message via Yahoo to roverhi
Re: Offshore novice question

If you run before the wind and seas without something to slow you down, the chances of burying the bow in the trough of the wave, being thrown beam on then rolled or pitch poled are very high. A very maneuverable boat with a really good helmsman can literally surf diagonally down the face of the waves without issue. The problem is an error by the helmsman and/or the boat not accelerating away from the breaking face of the wave will end up with the boat beam on and possibly rolled or pitch pole. Another problem with this method is distant covered. Not a good strategy without ample sea room.

Running off trailing a drogue, warps with tires, etc should keep you from surfing straight down the face of the wave and burying the bow with the ensuing disaster. The problem is having the right amount of drag. Too much and the boat will be subject to being overtaken by the breaking crest of the waves and pooped. Too little drag and you'll bury the bow in the trough. Most boats will probably be able to slow themselves enough that they won't have fear of pitch poling. Being constantly pooped isn't a life threatening happening but definitely is not a fun situation. It will probably result in a lot of water getting below soaking the interior of the boat, however. Unfortunately, most boats will not have the variety of gear to fine tune the amount of drag to get the ideal mixture of accelerartion and breaking to stay dry and safe.

All the options have been tried with success and some have tried several options in a single storm. Moitessier, when caught by an extremely powerful low in the southern ocean, first tried towing tires on warps. The boat was constantly being pooped so he decided to cut the warps and run before the storm. He was able to surf down the face of waves exceeding 50' but was on the helm for nearly two days before the storm passed beyond him. Moitessier had a boat with very long keel and deep forefoot so had exceptional directional stability and the steel boat with telephone pole masts was extremely stout. Perhaps the most important asset he had was an inside steering station. Not being exposed to the elements would go a long ways towards remaining sharp for the long time he was forced to spend steering the boat.
__________________
Peter O.
'Ae'a Pearson 35
roverhi is offline   Reply With Quote
Old 05-06-2015, 19:19   #25
Registered User
 
Muckle Flugga's Avatar

Join Date: Apr 2008
Location: Aboard the Ocean wave
Boat: 55' sloop.
Posts: 1,426
Re: Offshore novice question

Talking about that time (the three day heave to) made me dig through some old photos. The first one was taken in the hours immediately before the decision to heave to, and the second was after the first 12 hours hove to on that occasion. In the photo of the plotter the bow angle appears around 60 degrees but in fact was closer to 35 or 40 on average.
Attached Thumbnails
Click image for larger version

Name:	Immediately before heave to.jpg
Views:	176
Size:	69.4 KB
ID:	103262   Click image for larger version

Name:	Hove to.jpg
Views:	149
Size:	112.2 KB
ID:	103263  

__________________
‘Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance.’
Muckle Flugga is offline   Reply With Quote
Old 05-06-2015, 19:59   #26
Eternal Member
 
monte's Avatar

Cruisers Forum Supporter

Join Date: Jul 2011
Location: Australia
Boat: Lagoon 400
Posts: 3,650
Images: 1
Re: Offshore novice question

Fortunately we've only had the chance to test the theory on one occasion. We didnt necessarily need to but opted to do it in case conditions worsened, rather than wait till they did to 'experiment'
The weather we were seeing was pretty close to the forecast. I checked our log which says 30kn from 300 degrees. That was constant wind with some higher gusts, we were basically balanced throughout. Our position was between Tues and thurs on the grib.

Our COG is pretty much N so around 60 degrees off the wind. Waves were forecast at 6m from the NW but estimated closer to 5m from WNW. This put them and the wind at around 20 degrees to the bow.
You can see on the chart we were headed SW beforehand, which had us beam on to the seas and winds. The options were to run with them, or heave to/fore reach. The small Northerly track was around 6 hrs sailing. Enough for us to be confident the conditions weren't worsening, and that if they did we knew how to handle them comfortably. Definitely a worthwhile exercise for crew and boat. As a sidenote, were sailing with a fleet at the time and most of the fleet headed South with waves. Several had damage, torn sails, pooped etc, one ended up 100M from the African coast and a few diverted to Cape Verde for repairs.
Attached Thumbnails
Click image for larger version

Name:	Atlantic Crossing departure weather grib.JPG
Views:	155
Size:	180.9 KB
ID:	103264   Click image for larger version

Name:	hove to.JPG
Views:	147
Size:	123.7 KB
ID:	103265  

__________________
monte is offline   Reply With Quote
Old 05-06-2015, 20:06   #27
Registered User
 
Muckle Flugga's Avatar

Join Date: Apr 2008
Location: Aboard the Ocean wave
Boat: 55' sloop.
Posts: 1,426
Re: Offshore novice question

Quote:
Originally Posted by monte View Post
Fortunately we've only had the chance to test the theory on one occasion. We didnt necessarily need to but opted to do it in case conditions worsened, rather than wait till they did to 'experiment'
The weather we were seeing was pretty close to the forecast. I checked our log which says 30kn from 300 degrees. That was constant wind with some higher gusts, we were basically balanced throughout. Our position was between Tues and thurs on the grib.

Our COG is pretty much N so around 60 degrees off the wind. Waves were forecast at 6m from the NW but estimated closer to 5m from WNW. This put them and the wind at around 20 degrees to the bow.
You can see on the chart we were headed SW beforehand, which had us beam on to the seas and winds. The options were to run with them, or heave to/fore reach. The small Northerly track was around 6 hrs sailing. Enough for us to be confident the conditions weren't worsening, and that if they did we knew how to handle them comfortably. Definitely a worthwhile exercise for crew and boat. As a sidenote, were sailing with a fleet at the time and most of the fleet headed South with waves. Several had damage, torn sails, pooped etc, one ended up 100M from the African coast and a few diverted to Cape Verde for repairs.
Nice post and images. And yes. I wonder if the system had slowed and deepened, what would have happened to the yacht near the African coast. There are plenty of shallows and banks around there, in particular the famous Arguin bank where the Medusa was wrecked, though that was likely much further South. In any case, you did the right thing, most clearly.
__________________
‘Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance.’
Muckle Flugga is offline   Reply With Quote
Old 05-06-2015, 21:36   #28
Registered User

Join Date: Aug 2008
Location: New Bern, NC
Boat: Holman & Pye Red Admiral 36
Posts: 498
Re: Offshore novice question

Lepke said it best - learn to read a weather chart and the forecasts!

I was on a small container ship that ran from Virginia to Iceland and back, month after month, year after year. We saw some incredible stuff on that route.

When I joined I was an AB, but work my way up to Captain. We always plotted the weather - ever 6 hours a new chart. You learn by doing.

Unfortunately none of the Captains did anything about the weather forecasts - they just drove the ship in a straight line, trying to muscle thru. You don't muscle thru 40 to 60 foot seas - you go to 3-kt survival tactics. And beat the crab out of the ship, the cargo and the crew. And get to your destination late.

When I became Captain I had learned that even though we were a powered vessel, a container ship is in reality a "square rigged" sailing vessel - the containers being your sails. And I had decided that I wasn't going to beat the crap out of everything and everyone to just go in a straight line. On top of that, going into the weather slowed you way down and you got to your destination hours or days late.

So read your weather charts and plan ahead. When a big "onion" storm was headed my way, I just changed course to re-position the ship so the storm worked for us, instead of against us. But you had to plan ahead. I always figured where the ship and the storm would intercept in 72-hours and started re positioning.

Our storms went from west to east, so going to Iceland you wanted to be on the bottom of the storm (actually really big low's) and coming back you wanted to be on the top of the storm. You only had to re-position the ship perhaps 60 to 70-miles to get in the right spot; you picked up a lot of speed with the wind pushing you; you didn't burn as much fuel; you rode with the seas making for a much smoother passage; nothing got the crapped kicked out of it and you usually arrived in port ahead of time.

Win / win.

So learn how to read a weather chart or draw one from listening to the NOAA, Canadian or British ocean forecasts - it can keep you out of all sorts of trouble as well as save your life.
__________________
Doug Brown is offline   Reply With Quote
Old 05-06-2015, 22:47   #29
Registered User
 
MYTraveler's Avatar

Join Date: May 2010
Posts: 166
Re: Offshore novice question

As a powerboat, my equivalent of heave to is to put out the sea anchor. Rightly or wrongly, I am pretty well convinced that my boat can handle ridiculous seas that way. My two concerns are getting the chute deployed (since in heavy seas the bow of my boat can fling a man 50 feet) and chaffing. Other than that, the hatches will be closed, the engines off, and the crew and I sleeping it off.
__________________
MYTraveler is offline   Reply With Quote
Old 06-06-2015, 02:57   #30
Registered User
 
Muckle Flugga's Avatar

Join Date: Apr 2008
Location: Aboard the Ocean wave
Boat: 55' sloop.
Posts: 1,426
Re: Offshore novice question

Quote:
Originally Posted by Doug Brown View Post
Lepke said it best - learn to read a weather chart and the forecasts!

I was on a small container ship that ran from Virginia to Iceland and back, month after month, year after year. We saw some incredible stuff on that route.

When I joined I was an AB, but work my way up to Captain. We always plotted the weather - ever 6 hours a new chart. You learn by doing.

Unfortunately none of the Captains did anything about the weather forecasts - they just drove the ship in a straight line, trying to muscle thru. You don't muscle thru 40 to 60 foot seas - you go to 3-kt survival tactics. And beat the crab out of the ship, the cargo and the crew. And get to your destination late.

When I became Captain I had learned that even though we were a powered vessel, a container ship is in reality a "square rigged" sailing vessel - the containers being your sails. And I had decided that I wasn't going to beat the crap out of everything and everyone to just go in a straight line. On top of that, going into the weather slowed you way down and you got to your destination hours or days late.

So read your weather charts and plan ahead. When a big "onion" storm was headed my way, I just changed course to re-position the ship so the storm worked for us, instead of against us. But you had to plan ahead. I always figured where the ship and the storm would intercept in 72-hours and started re positioning.

Our storms went from west to east, so going to Iceland you wanted to be on the bottom of the storm (actually really big low's) and coming back you wanted to be on the top of the storm. You only had to re-position the ship perhaps 60 to 70-miles to get in the right spot; you picked up a lot of speed with the wind pushing you; you didn't burn as much fuel; you rode with the seas making for a much smoother passage; nothing got the crapped kicked out of it and you usually arrived in port ahead of time.

Win / win.

So learn how to read a weather chart or draw one from listening to the NOAA, Canadian or British ocean forecasts - it can keep you out of all sorts of trouble as well as save your life.
Great post, and can't disagree with a word nor would I wish to. However, of course, in a small sailboat we can't always avoid the weather, and as you know in the North Atlantic, for example, not infrequently the systems are 1500 miles wide and fast moving. Can be hard to get out of the way of that in a sailboat!

The longest heave to I have ever done, described in this thread, was not to survive a survival storm, but rather to weather a gale between two much larger and more intense systems, a tropical revolving system to the North and a deep low crossing the Tasman to the South. This is one of the reasons I like, use and trust heaving to. Usually it is only for a half dozen hours or half a day, but in reference to weather foresigh, it affords the ability to stop and let systems ahead pass through. Obvously active sailing around can be done, but sometimes a heave to is the most practical means and a great tool.

Weather forecasting has improved immensely in the past 25 years, and of course it is also true that in the higher latitudes the predictability of systems is very much higher over all. This is one of the reasons why boat design in the same period has veered away from the traditional tough as nails and take all comers style and toward lightly built cruiser racer. It is simply less common these days to be caught out by the worst weather. The North Atlantic can be extremely violent for sure, and I learned to sail and cut my teeth as skipper in the waters of the North of Scotland, so am well used to watching them come across that stretch. I will be crossing it again W to E in three weeks. In the old days the hand drawn synoptics was what we had to go by, and a look at the general chart of the North Atlantic was usually enough to give a very good view of the next 3 to 5 days and perhaps more. I still use old schools synoptics for the NA as well as more modern resources such as gribs. My preferred source for traditional synoptics is the German weather service found at:

Wetterkarte, DWD, Bodenwetterkarte

Of course I use more modern services as well.

But in the areas between the tropical and temperate zones, the systems are far more stochastic and the models frequently break down. This is particularly true in regions like the central and North Tasman and the South Pacific between the Cook Islands and Tonga, where the likes of gribs have a really hard time modelling interacting tropical and Southern Ocean depressions and where often an area of truly intense tropical activity will be plotted as an area of virtually no winds with a strange isobar pattern almost akin to an arch or loop pattern of a fingerprint, mirrored on itself along the base.

In that way it is still possible to identify where the computers are mismodelling and to mistrust the area, but interpretation is a whole lot harder in those intertropical zones.

It is precisely because of the failure of the most modern weather models that I had to heave to for three days in the first place, as while the South Tasman low was predicted (though ended up being larger and deeper than predicted) the supercell coalescing into a massive rotating tropical depression to the North was not. Believe me the weather was observed, examined and discussed on a three times a day basis prior to departing the Bay of Islands.

And it turned out to be flat wrong. This is a common finding in those waters. Accuracy beyond a couple of days is really very poor in the central Tasman area to the North of NZ, and the crossing takes longer than that! In my case the projected passage was 6 days, and I checked in at Vuda Point eleven days after departure.

Upshot of all this is, if you spend enough time in the deep oceans in a sailboat or other small craft, there will come a time when you simply cannot avoid, and must survive, a severe storm at sea. And that's where knowledge, practise, and experience of the various tactics comes in. There is no silver bullet, there are only a suite of storm defense tactics from which we are to select depending upon encountered circumstances. Heaving to has its place as a prominent and immensely useful technique among them.
__________________

__________________
‘Structural engineering is the art of modeling materials we do not wholly understand into shapes we cannot precisely analyse as to withstand forces we cannot properly assess in such a way that the public at large has no reason to suspect the extent of our ignorance.’
Muckle Flugga is offline   Reply With Quote
Reply

Tags
novice, offshore

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
How Far Offshore is Offshore? Jay Jennings General Sailing Forum 57 30-03-2017 15:16
Novice Question/Yanmar 4JHE & Pump Oil formrteki Engines and Propulsion Systems 10 20-10-2016 06:53
How OffShore to be an 'Offshore" passage? twistedtree Seamanship & Boat Handling 68 03-02-2013 15:39
Novice with Overwhelming Urge To The Sea and One Question arisussman Meets & Greets 4 31-03-2008 17:33
Hello from a total novice Stella Meets & Greets 10 18-07-2007 13:46



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:22.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.