Cost/Benefit Ratio of Offsoundings weather reports

[Adelie]

Originally Posted by BillKny

The OP has come to the completely uninformed conclusion that paying to get weather forecasts offshore is a waste and wants people to support his opinion. There are two reasons that this might be true. He can't afford the service and wants to feel better about that, or he doesn't understand how to use it and will feel better if he can convince himself that it has no real value and he isn't missing anything. Or maybe he's just a troll stirring the pot for entertainment....

Unless you know the member personally you can not know if they have come to a conclusion. If they had come to a conclusion, I don't think they would have started the thread in the first place. Unless they enjoy the abuse, CF has a habit of beating up on newbies.

Nor can you really know what reasons they might have for a conclusion.

At least not until he/she informs us what the conclusion is and the reasons they have for it.

[jdazey]

Originally Posted by BillKny

The OP has come to the completely uninformed conclusion that paying to get weather forecasts offshore is a waste and wants people to support his opinion. There are two reasons that this might be true. He can't afford the service and wants to feel better about that, or he doesn't understand how to use it and will feel better if he can convince himself that it has no real value and he isn't missing anything. Or maybe he's just a troll stirring the pot for entertainment.

As an experienced offshore passage maker and delivery captain, I update my weather information every 12 hours and evaluate my route decisions with each new forecast. The idea that this information is somehow not "actionable" is just hooey.

The focus of this thread has been all about storms and dangerous weather, and that certainly can be a factor, but what about calms and head winds? I far more often adjust my route to get MORE wind, or wind from a better direction.

Just as an example: Knowing days ahead of time a front is going to pass through, exactly WHEN, and the wind direction shift that will accompany it is EXTREMELY valuable information to the knowledgable sailor. It can make a HUGE difference in the passage time by allowing me to know when it makes the best strategic sense to tack or gybe. If the value of advance knowledge of a 150 degree wind shift is lost on you, then there isn't much I can do to convince you otherwise, and I am not going to try.

The idea that the only weather information that has value is what you can SEE is just wrong.

This.

[Breaking Waves]

We have done two circumnavigations, the first one we essentially did not get external weather while at sea (this was mostly before consumer communication and gps satellites). The second one we got weather (gribs) on-demand and I mostly did full-on continuous weather routing.

The first trip was (mostly) less stressful because we did not know or worry about what was coming over the horizon. We just dealt with it when it arrived.

The second trip we used the advance weather information quite frequently to make a more efficient passage (find favorable wind directions, get on the better side of a low, avoid becalmed spots, etc).

In low-pressure systems, the most intense winds are often in a quite small zone. If you can identify and correctly move even 50 miles further away you can often drop the wind speed by 50%. If you can get to the correct side of the low you can have favorable wind directiosn rather than windwinds. Both of these things you can often (but not always) do when you get days of advance warning.

But you DO need knowledge and experience to use the weather information effectively - there is quite a bit of subtly to correctly interpreting it - especially identifying how much confidence you should have in the information. It is not so uncommon for the 5 day forecast to be wrong and you dont want to have sailed well off route to try for favorable winds and then have it all turn out to be something else. You get a very good feel for this when you build experience and knowledge.

Between the two approaches (having weather info and not), I would always now pick having it if given the choice. But I would not criticize someone for picking the other.

[Adelie]

While there are folks here with more experience than
Breaking Waves, there aren’t many.

[Mara Mae]

Originally Posted by BillKny

The OP has come to the completely uninformed conclusion that paying to get weather forecasts offshore is a waste and wants people to support his opinion. There are two reasons that this might be true. He can't afford the service and wants to feel better about that, or he doesn't understand how to use it and will feel better if he can convince himself that it has no real value and he isn't missing anything. Or maybe he's just a troll stirring the pot for entertainment.

As an experienced offshore passage maker and delivery captain, I update my weather information every 12 hours and evaluate my route decisions with each new forecast. The idea that this information is somehow not "actionable" is just hooey.

The focus of this thread has been all about storms and dangerous weather, and that certainly can be a factor, but what about calms and head winds? I far more often adjust my route to get MORE wind, or wind from a better direction.

Just as an example: Knowing days ahead of time a front is going to pass through, exactly WHEN, and the wind direction shift that will accompany it is EXTREMELY valuable information to the knowledgable sailor. It can make a HUGE difference in the passage time by allowing me to know when it makes the best strategic sense to tack or gybe. If the value of advance knowledge of a 150 degree wind shift is lost on you, then there isn't much I can do to convince you otherwise, and I am not going to try.

The idea that the only weather information that has value is what you can SEE is just wrong.

LOL 1. I am not a troll. 2. I am not looking for support of my opinion. 3. I am looking for practical nautical experience that indicates that the technologies that make weather reports available to recreational sailors make a measurable contribution to the ocean sailor's margin of safety. 4. I have passed the RYA Day Skipper theory course. 6. I am a retired commercial bush pilot (air) in Northern Canada, so my opinion is not completely uninformed regarding navigating through weather cells with passengers and the importance of forecasts. 7. I am trying to interpolate my experience of air travel at 120 kts to sea travel at 4 kts. 8. I do own an offshore sailboat. I sail the Gulf of St-Lawrence and the North Atlantic. I check the weather before going out and file a sail plan if travelling off soundings. 9. So far my experience with marine weather forecasts is to make a go or nogo decision which is similar to professional aeronautical decisionmaking 10. I also have a PhD and my question is perhaps best understood as a hypothesis that I am proposing to see if it can be disproven with empirical data. 11. Simply put, if a state of the art Iridum/Predictwind system indicates a low pressure system developing 20-30 miles away along my track, with a hull speed of 6 kts what could I possibly do to avoid the weather system?

[Paul L]

Originally Posted by Mara Mae

....... 11. Simply put, if a state of the art Iridum/Predictwind system indicates a low pressure system developing 20-30 miles away along my track, with a hull speed of 6 kts what could I possibly do to avoid the weather system?

You are setting up a situation that begs the question, but I'll bite anyway.
Firstly IridiumGo PW is not state of the art. For offshore passage making the issue is downloading Grib files. It doesn't matter how you do it or what system you use to display them. The Gribs give you wind, pressure, seas, current over a large geographic area predicted out up to 14 days, but offshore you are typically using up to a week. The major models are updated twice or 4 times a day.
So traveling on a 4kt sh*tbox, or a typical 6 kt cruiser weather that is 20-30miles away in your example is too close to get a lot out of the latest forecast, other than how deep is it projected to go.
What is far more important is how does the wind and seas change over the next 100 to 400 miles. I just completed an 800 mile passage. We download Gribs once a day (unless things are volatile then maybe twice a day) and make course adjustments based on them,. On this passage it was primarily to tune how much easterly to add to the course to be able fall off to make the compression zone at the end of the trip more comfortablem less boat breaking. Every passage has different needs and it is foolish to do ocean passages without a method to obtain daily weather.

[Chris31415]

I feel like your question has been answered.

Grib files can provide days of forecasts. Knowledge is power. You can be 200-300 miles from your current location in that time. This can allow you to:

1. Completely avoid a weather system, depending on it’s size and speed.

2. The “weather system” is not uniform. There can be significant differences in wind speed, direction, etc. and you can position yourself appropriately. Better to be on the edge of a hurricane than heading into the eye.

3. You can optimize your passage, altering your course to minimize your passage time and minimize uncomfortable conditions.

[japawil]

Originally Posted by Mara Mae

LOL 1. I am not a troll. 2. I am not looking for support of my opinion. 3. I am looking for practical nautical experience that indicates that the technologies that make weather reports available to recreational sailors make a measurable contribution to the ocean sailor's margin of safety. 4. I have passed the RYA Day Skipper theory course. 6. I am a retired commercial bush pilot (air) in Northern Canada, so my opinion is not completely uninformed regarding navigating through weather cells with passengers and the importance of forecasts. 7. I am trying to interpolate my experience of air travel at 120 kts to sea travel at 4 kts. 8. I do own an offshore sailboat. I sail the Gulf of St-Lawrence and the North Atlantic. I check the weather before going out and file a sail plan if travelling off soundings. 9. So far my experience with marine weather forecasts is to make a go or nogo decision which is similar to professional aeronautical decisionmaking 10. I also have a PhD and my question is perhaps best understood as a hypothesis that I am proposing to see if it can be disproven with empirical data. 11. Simply put, if a state of the art Iridum/Predictwind system indicates a low pressure system developing 20-30 miles away along my track, with a hull speed of 6 kts what could I possibly do to avoid the weather system?

It would seem as a retired bush pilot the importance of weather forecasting should be self evident.
It appears your question is based around your speed of travel relative to the speed of a weather system. It’s elementary actually; the slower you go the more important forecasts become.
Perhaps your hung up on the thought that you wouldn’t be able to completely avoid a system should one be detected in your vicinity while traveling at 4-5 knots? Well, that’s true. However, the further in advance you know of a systems development and track, the more informed and affective a decision you’re able to make.
Remember major weather systems don’t just “pop” into existence 30 miles away. They form over time usually with indications that…well….”forecast” their formation a general track. Not perfectly I grant you.
Now squalls…. that’s a different story.

[wholybee]

It really depends on when, where, and how, you sail. If you are doing tradewinds sailing outside of the hurricane season, it is very unlikely you will experience dangerous weather. From time to time it might get uncomfortable, but not so much that you will need to divert from a near straight line course to your destination. The weather information is nice to have, but isn't likely going to change anything.

However, that weather information extends the sailing season, allowing you to sail when dangerous weather is still infrequent, but happens often enough it isn't safe to sail without it. It also make high latitude sailing safer, when weather changes will be faster and more extreme.

Also, the length of the passage plays a part. My longest passage was 31 days. That was much further out than any model can give any idea of. If your passage is less than 14 days, you will not have an accurate weather forecast that far out, but you at least should know it will be safe. I met a lot of sailors that checked the weather up until the time they left, but had nothing once they did. At 21+ days, stuff can be there that there was no indication of at all.


I found during my circumnavigation that I checked weather 2x per day, and very very rarely diverted. When I did, I don't think I gained much if anything. More often than bad weather, I diverted looking for better wind, and didn't get to it anyway.

If you are racing (my leg from SF to Hawaii was in the Pacific Cup) then you might make alterations to you planned course more often, but not for safety, but to gain a few hours on your arrival. Interestingly, during pre race planning, The difference calculated between the fastest course and a straight line was 45 minutes for a predicted 12 day sail. The fastest course added 500nm. So for casual cruising, it often doesn't make sense to add those miles.

[wingssail]

Originally Posted by Mara Mae

I am wondering about the practical benefit of receiving weather reports while on ocean
passages. Perhaps a dumb question but if you are mid-ocean and receive a hurricane warning how will the information improve your situation?

For ocean passages receiving weather information is absolutely essential.

For centuries sailors did without offshore weather information. Many vessels were lost. Now, at least we have the benefit of advance warning.

However, it is not text or verbal weather forecasts which are of so much value, it is the overall synoptic situation which is revealed with GRIB files and viewers, WEFAX, and Satellite photos. All of which are available via various methods while offshore.

Not only do these allow you to anticipate and possibly avoid bad weather, they allow you to optimize your route to shorten the time you are exposed.

Your question as to the advisability of just staying prepared and facing the storms which you see visually is probably not the best way to achieve an old age.

[Stu Jackson]

Originally Posted by Mara Mae

.................
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9. So far my experience with marine weather forecasts is to make a go or nogo decision which is similar to professional aeronautical decisionmaking 10. I also have a PhD and my question is perhaps best understood as a hypothesis that I am proposing to see if it can be disproven with empirical data. 11. Simply put, if a state of the art Iridum/Predictwind system indicates a low pressure system developing 20-30 miles away along my track, with a hull speed of 6 kts what could I possibly do to avoid the weather system?

Thx for expanding on your background.


9. It struck me that flying is much different than sailing offshore simply because of the length of the "voyages" beyond those of simply speed.
10. With a PhD, wouldn't one already know the difficulties of proving a negative?
11. This is also a false hypothetical, because with that gear (and others available for longer range forecasts well beyond 20-30 miles), one would have been able to "see" developing patterns much further out in an order of magnitude of at least 10x.

The slower you go the much more important long range information becomes.


Cost/benefit? What's your boat and your life worth to you?

[Fore and Aft]

Mara Mae I can see your point. It's like repeatedly looking at the weather forecast and changing paths while walking to the beach a hundred miles away. It's not like weather forecasts are 100% accurate.
It's a good point you raise and I am going to ask some of my clients who sail offshore. Certainly some of them just suck it up and take whatever weather is coming there way.
Cheers

[wingssail]

I am going to give you a real example of the benefit of offshore weather information.

We were one of about 30 yachts underway from Fiji and Tonga to New Zealand. We had a good forecast for departure and expected moderate E to NE winds the whole way, for an expected 7-10 day passage.

On day 4 we received a WEFAX via SSB/Pactor showing a dip in the isobars indicating a develping deep low pressure system to the NW of us moving SE. Grib files and subsequent WEFAX indicated a sub 900mmb low with high intensity winds.

Several boats diverted to Minerva Reef. Those of us too far south to get back to Minerva headed east into the building SE winds to avoid being blown west past the top of New Zealand.

The weather information made it possible to take action far ahead of the advent of any visible sign of the storm (and baraometric pressure revealed little to be alarmed about).

Most boats used that information to take shelter. Of the few that were unable to, five boats and four lives were lost. WINGSSAIL - Cruising Log of Wings - Serendipity 43 - Fred Roswold & Judy Jensen

We took action which helped us deal with the conditions and we arrived in NZ without significant problems.

Without the weather information I believe several other boats would have been lost.

[donradcliffe]

Originally Posted by Snore

This is a potential ‘Darwin Awards’ issue.

Satellite weather is a complete waste of money- until things go sideways.

As a yacht delivery ‘captain’ I would not think of moving a boat offshore- be it a $100k boat or a $2mil high-end yacht- without getting weather twice a day.

Getting weather updates is safer AND makes me more productive.

Amen, brother.

[Adelie]

Originally Posted by Stu Jackson

…..
Cost/benefit? What's your boat and your life worth to you?

Are you saying that if he doesn’t get a source for GRIBs he’ll probably die on passage?

How about you Stu? Do you have SSB/Pactor and an Iridium, and AIS transceiver and a life raft and a backup life raft and a crash bulkhead near the bow of your boat and seal floatation chambers elsewhere in the boat and an EPIRB and PLB and a trysail and a hurricane jib and have you cut down you mast to help you deal with heavy weather? If not why not? What's your boat and your life worth to you?

I think you win today award for the most histrionic post.