31 replies to this topic

[Estar]

Regarding weather and routing discussion on a couple of the other threads . . . .

There are a bunch of free grib viewers available, but this is the first good free routing package I have seen.

Downloads at Virtual winds. Get the version 3.3 plus the 3.3.3 patch. The program and help files will run in English, but the forum at http://virtual-winds.com/forum is in french

It's from a group of French open source developers. I don't have any connection/involvement with it to it, except to be delighted to see a decent free package now available. It's not as powerful as something like expedition, but still quite useful, and they are very actively working on/improving it.

Screenshot:
 screenshot.jpg   169.31K   77 downloads

[WHL]

Nice !

[boomer]

Neat!

Aren't there more out there as well, without routing.

Seems to me I remember seeing other open source software more then a few years back.

They may not have the routing, but doing one's own routing with gribs is perfectly fine for many.

http://www.grib.us/

http://www.globalmar...b_downloads.php

http://www.predictwind.com/grib-files/

http://weather.maila...e-Grib-Services

[Mark Morwood]

Great find. I'm off to try it out. And as an added benefit for me, they also have a native Mac version, so I won't have to run it under VMWare.

Thanks for the link.

Mark.

[monsoon]

Great find. I'm off to try it out. And as an added benefit for me, they also have a native Mac version, so I won't have to run it under VMWare.

Thanks for the link.

Mark.

Mark,

Where did you see the Mac version? I could not find it.

[dinghydoc]

Great find. I'm off to try it out. And as an added benefit for me, they also have a native Mac version, so I won't have to run it under VMWare.

Thanks for the link.

Mark.

Mark,

Where did you see the Mac version? I could not find it.

Way upper right corner of the download page there is a link to files for Apple....

 temp.png   21.46K   6 downloads

[robalex117]

for gribs I use this ipad app. I think it cost $3, very easy to use. PocketGrib

Neat!

Aren't there more out there as well, without routing.

Seems to me I remember seeing other open source software more then a few years back.

They may not have the routing, but doing one's own routing with gribs is perfectly fine for many.

http://www.grib.us/

http://www.globalmar...b_downloads.php

http://www.predictwind.com/grib-files/

http://weather.maila...e-Grib-Services

[rattus32]

Great find. I'm off to try it out. And as an added benefit for me, they also have a native Mac version, so I won't have to run it under VMWare.

Thanks for the link.

Mark.

Mark,

Where did you see the Mac version? I could not find it.

Try ZyGRIB - It's also French but they actually bother to offer English versions of their pages (and cheerfully admit they are in Frenglish):

http://www.zygrib.or...age=abstract_en

You can also use files downloaded via ZyGRIB in the new OpenCPN GRIB plugin, which then opens the world of OpenCPN (including routing) capabilities. All are also Linux compatible.

Why cripple yourself with Windows-only packages (and hardware)?

Edit: oops - missed the "apple files" link on the Virtual Winds site.

[Ajax]

Excellent, thanks!

[Tucky]

Nice to see the Mac versions starting to come back full circle (wasn't Maxsea originally Macsea?).

[Estar]

OpenCPN (including routing) capabilities.

Does openCPN do routing? If so how (plug in add-on?)? Last time I looked at it I did not see any routing.

I have been playing with the virtual winds program for the vendee globe thread, and its pretty impressive - easy to use and called JPD's gybe to the SW (with negative vgm) well before it was obvious to the eye.

[Ajax]

You can manually make routes, not sure if it automatically routes. My version does not, but I'm not running the latest version.

[us7070]

i'm playing a bit with this, and i got it to optimize a route, but i can't figure out how to view the details of that optimal route - the things you would see in the "results" page of expedition.

[Estar]

i'm playing a bit with this, and i got it to optimize a route, but i can't figure out how to view the details of that optimal route - the things you would see in the "results" page of expedition.

In the editing routing screen, you check 'convert to route'. Then you go to the edit route screen and look at 'route details' tab which gives you all the normal stuff.

I had to ask about that also.

[us7070]

thanks.

i don't see any kind of marks management page - am i just missing it?

[Estar]

thanks.

i don't see any kind of marks management page - am i just missing it?

I also asked that . . . They expect you to import your marks, and 'manage' them elsewhere.

I have not played with the 3 different types of marks yet, and don't really understand the differences; but this is an area where Expedition does appear to have much greater flexibility with types of marks (starboard or gate) and exclusion zones. But those things are mostly more useful for racers than cruisers.

[us7070]

be interesting to compare routing between expedition and this for the same polars.

one thing i see right away, is that it seems that in virtual winds, a boat is always on one tack or another, whereas in expedition, the route can have a segment hat is inside your tacking (or gybing) angles - often when there is a corridor of wind - and you are supposed to just play the shifts along the corridor, with expedition indicating on which tack you will spend more time.

Nick says he is currently in the process of doing a major re-write of the optimization part of expedition.

[Estar]

in virtual winds, a boat is always on one tack or another, whereas in expedition, the route can have a segment hat is inside your tacking (or gybing) angles - often when there is a corridor of wind - and you are supposed to just play the shifts along the corridor, with expedition indicating on which tack you will spend more time.

I don't know if you picked up on this, but the group developing virtual winds did it to drive the autopilots on the French virtual sailing games. So, it definitely needs to output courses that the autopilot can directly steer.

[us7070]

Estar - in the Vendee thread over in ocean racing anarchy, you mentioned editing polars.

are you doing that in Expedition?

I don't see any polar editing in Virtual Winds.

The Expedition polar editing is great - I have been using it a lot recently building polars for two of the boats i sail on.

There is a dedicated program for polar editing - called "Polar Manager" - but it's pretty expensive.

[Estar]

Estar - in the Vendee thread over in ocean racing anarchy, you mentioned editing polars.

are you doing that in Expedition?

I don't see any polar editing in Virtual Winds.

The Expedition polar editing is great - I have been using it a lot recently building polars for two of the boats i sail on.

There is a dedicated program for polar editing - called "Polar Manager" - but it's pretty expensive.

All I was doing was playing with the percent of base polar used, not changing the shape of the curves. There's a function for that in virtual winds. I don't have anywhere enough vendee information to try to adjust the shape of the curves - and don't think I need to in order to look at the weather impact on the fleet which is all I am really trying to do. I am not trying to compare one boat's performance to another - I will leave that to the designers.

For Hawk's polars, where I do have a lot more performance information, I have used a number of programs for the polars but have ended up just maintaining them in excel. I just try to maintain two simple polars (a 'full speed/flat water' and an 'offshore/fatigued'). There are so many variables that effect the polars (whether we are hand steering or autopilot, whether its Beth's watch or mine, whether its night or day, etc etc) that I have never seen the point in trying to spend a lot of time 'super fine tuning' it. I can see for round the buoy racers who sail in very similar conditions each time (say 5-15kts and flat water) it might be worthwhile (but even then, there are issues which make it suspect, such as often the log is not completely linear calibrated), but for us there are +-20% externalities so a 'near enough' polar is all that's worthwhile to seek.

[Tucky]

There are so many variables that effect the polars (whether we are hand steering or autopilot, whether its Beth's watch or mine, whether its night or day, etc etc) that I have never seen the point in trying to spend a lot of time 'super fine tuning' it.

Ok, out with it- whose polars are faster?

[WHL]

I installed a mux on one boat I race so I could get a NMEA feed to iRegatta on my iPhone from the Ockham instruments. iRegatta has a neat section of the app which can import polars, and then update them wilth your actual performace. Updating the polars this way means that Expedition doesn't have to be running to creae strip charts to study The file can be re-exported to Expedition or whatever other app is used. It's too bad that there isn't a fixed standard in the format of a polar data file.

[us7070]

Estar - in the Vendee thread over in ocean racing anarchy, you mentioned editing polars.

are you doing that in Expedition?

I don't see any polar editing in Virtual Winds.

The Expedition polar editing is great - I have been using it a lot recently building polars for two of the boats i sail on.

There is a dedicated program for polar editing - called "Polar Manager" - but it's pretty expensive.

All I was doing was playing with the percent of base polar used, not changing the shape of the curves. There's a function for that in virtual winds. I don't have anywhere enough vendee information to try to adjust the shape of the curves - and don't think I need to in order to look at the weather impact on the fleet which is all I am really trying to do. I am not trying to compare one boat's performance to another - I will leave that to the designers.

For Hawk's polars, where I do have a lot more performance information, I have used a number of programs for the polars but have ended up just maintaining them in excel. I just try to maintain two simple polars (a 'full speed/flat water' and an 'offshore/fatigued'). There are so many variables that effect the polars (whether we are hand steering or autopilot, whether its Beth's watch or mine, whether its night or day, etc etc) that I have never seen the point in trying to spend a lot of time 'super fine tuning' it. I can see for round the buoy racers who sail in very similar conditions each time (say 5-15kts and flat water) it might be worthwhile (but even then, there are issues which make it suspect, such as often the log is not completely linear calibrated), but for us there are +-20% externalities so a 'near enough' polar is all that's worthwhile to seek.

Certainly there are issues with instruments - if they are not calibrated, you will not get good polars.

Anyway, it's not just that racers want "better" polars, it's also that often the boat configuration is changing. - a taller rig for example - so wee need to make new polars.

[Ajax]

Ok so far, I've installed and played with Ugrib. I've downloaded Virtual Winds but I ran out of time, so I'll install and tinker with it tonight.

This stuff is very cool!

Talk to me about manual routing:

So, I've downloaded a GRIB good for 5 days. (Ugrib even animates the grib over the 5 days, sort of the way that CBOFS does) I have an origination and a destination. I am supposed to plot a course (using OpenCPN for example) that gets me to my destination while utilizing the most favorable winds shown in the GRIB, and avoiding nasty stuff, or winds that might greatly impede my progress. If my destination requires crossing the Gulf Stream, I use this information to coordinate my crossing, so that I have a smooth passage through the stream.

Is that about right?

When attempting to cross the stream, what conditions am I looking for? My guess is that ideal crossing conditions are breezes that are roughly in line with the direction of flow of the Gulf Stream, that also are not too strong.

I'm really feeling driven to make a lap around Delmarva next year, and I want to be proficient at this to help me plan and understand.

[us7070]

In practice, it's much better to view gribs in a navigation program, rather than using a separate grib viewer like ugrib.

that way, you can advance the gribs, and make your route on the same screen

I don't use OpnCpn but I guess this would be possible.

it can be difficult to know how far to advance your position as you advance the gribs - that's why optimization programs are so useful.

In Expedition, for example, you don't have to let it find your optimal route..., you can specify a route, and let Expedition use your polars to advance you along that route, showing you exactly the conditions you can expect on that route at each timestep.

As far as crossing the gulf stream goes - firstly, it's a bit unpredictable..., winds can be significantly stronger than forecast in numerical models. Also, it depends on whether you are racing, and looking for the fastest course, or cruising and looking for the most comfortable crossing. generally, if the wind has a significant component against the current direction, you can get uncomfortable seas. 90 degrees is usually fine. some people, as a rule of thumb, try to avoid being on port tack when crossing the stream going to Bermuda, but really every crossing is different, and I've been on port a few times, and it's been fine.

Obviously, the subject of dealing with the gulf stream on the way to Bermuda is a subject that can be discussed forever..., I've done a bunch of Bermuda races, and I learn something new each time.

[Ajax]

Cool, thank you. Hopefully I get to work with OpenCPN and Expedition tonight.

[rattus32]

Ajax, if you figure out how to complete (i.e close off) a route in OpenCPN I'd like to hear about it.

I did get an answer from the OpenCPN folks that v3.3.1105 had a number of qtVlm interface changes such that the interface is broken at the moment.

[WHL]

Cool, thank you. Hopefully I get to work with OpenCPN and Expedition tonight.

Ajax,
If you're going to try Expedition, there's another useful tool for assisting Expedition in its routing, and that's a feature called Race Notes. It's on the "Sail" tab of the menu bar where you'll also find Polars and your Sail Chart definitions (i.e. which sail to use in what wind speed and wind angle range)

Race Notes is a tool where you can define a polygon or area you want Expedition to avoid in its routing. It has other uses too, but for routing on coastal sailing, it's very useful to avoid the hard bits by encircling them with Note. You have an option to avoid the area in routing or not. Here's an example of race Notes I used last summer sailing up LIS with "Mung Breath" to Newport.

You can also use them for offshore passages too by encircling areas you want to avoid e.g. typical high pressure zones, areas that may be foggy at certain times of year, shipping routes.... etc...

 Expedition Race Notes.jpg   128.87K   21 downloads

[WHL]

Ajax,
Here's the routing (in blue) showing Expedition avoiding the red Race Note areas using today's grib
 Expedition routing avoiding Race Notes areas.jpg   247.05K   34 downloads

[ice9a]

In practice, it's much better to view gribs in a navigation program, rather than using a separate grib viewer like ugrib. that way, you can advance the gribs, and make your route on the same screen

I am going to suggest a slightly different perspective, at least for cruising. I don't often use routing software at sea. I usually just flip thru the gribs (using viewfax - a standalone grib viewer). I don't like sitting at the nav station staring at a computer screen at sea, and I can usually get all I need to know by flipping quickly thru the gribs. I know how far we will go each day in screen distance so can just move my eye along, and I occasionally jot down a lat/lat long way point to aim at, if there is something to go for (or away from).

Very rarely, when we are navigating quite close around a fast moving feature (usually a low), I will pull up the routing perhaps 24 & 12 hrs in advance to see when it's says to tack or jybe to best effect.

A lot of the Bermuda racers I know use the route movement as you describe (to see where they will be as they flip thru the gribs) but don't use the optimized routings. They have found the routings are too often driven too far off the GC course by small differences in forecast winds that are not actually there. They prefer their judgement looking at the wind and current gribs, and real time sat pictures. That's a very short passage for routing, as a cruiser I would wait for a decent weather window and then just go for it (looking at the gribs)

I do use the routing programs when ashore looking for a weather window. I can develop a detailed baseline plan for the whole passage, and can look closely for any things I should watch for as future developments, and it helps to explain/discuss the plan with Beth, and I am not fatigued and don't mind looking at the screen.

Ok, out with it- whose polars are faster?

I am faster daysailing (Better sail trim, sail selection and helming) and she is faster on long passages (higher work rate when tired)

[Roleur]

Anyone figured out how to export a .gpx file (route) out of qtVlm? I read that is possible, but I'll be damned if I can figure out how. I'm using a Mac and I wonder if the "feature" is still missing for the Mac.

Otherwise this seems like great routing software considering the price. I wouldn't use it for navigation, just creating optimal routes and then export.

For editing Polars, it looks like the only option is to edit the .csv directly.

[marineboy305]

I came to this forum to learn more about the qtVLM. Anyone by now has a tutorial in English? It could be a really good educational software for a beginner navigator but it just lacks
a short tutorial that lets me complete a simple "virtual" navigation and move on to more advanced subjects.

someone started talking about a software called "Expedition" that seems to be highly regarded as more friendly and scientific, etc. but it costs USD 1,295 or so and it is not for me.
Expedition licence$1,295.0