Vendee Globe 2020

H

Herman

Super Anarchist
2,272
1,968
The Netherlands
Weather update + AIS positions

After updating Anaconda Navigator and playing with Python for half a day, I succeeded in running the AIS-script posted up thread earlier and import the positions for the first 8 boats into OpenCPN. Compared the reported 17:30 positions with their AIS-positions. As the timestamps for AIS differ from the 17:30 timestamp and benchmark, there are differences. For some boats these delta's are bigger than I can explain atm. Either the AIS scraping is not accurate enough for some boats, or their reported positions do not match the 17:30 timestamp. My guess is the latter, as AIS does not lie and there are almost no other boats in the area that could trigger a false AIS-report. And AIS speed and heading confirm it's a VG-boat when checking the offical tracker.

DELTA AIS-position versus Reported 17:30 in NM and time:

  • Dalin 9 nm and 35 minutes (seems accurate)
  • Burton 23 nm and 87 minutes (not OK) 
  • Seguin 36 nm and 29 minutes (not OK)
  • Herrmann 48 nm and 88 minutes (not OK)
  • Le Cam 53 nm and 42 minutes (not OK)
  • Bestaven 25 nm and 55 minutes (not OK)
  • Ruyant 18 nm and 51 minutes (seems accurate)
  • Dutreux 24 nm and 35 minutes (not OK)

Now to the weather routing. In the top-8 boats are 3 without a foiler, that is not bad. Conditions (e.g. sea state) have not been ideal for foiling lately. As the sea seems to flatten a bit around 3 meters for Dalin and Ruyant, these foilers should be able to get their extra advantage until the next LP comes in Tuesday. If sailing on the good bow for Ruyant.

I changed the virtual waypoint towards Cape Leeuwin, 70 nm above the AEZ. After 120 East the AEZ moves to the south, so this corner is a natural waypoint. Adjusted polars for Dutreux and Seguin for non-foiling.

ECMWF and GFS align, more or less, as usual. Not guaranteed on a boat level.

Routing table is in pic 1. Rough rides again predicted due to the new wind coing in from the west for most boats. Dalin, Ruyant and Bestaven have very high max winds in the 40s and 50s kts. I can understand that they want to stay out of this in order to keep the boat in one piece. A detour more to the north could be necessary. See pic 3 for routing Dalin with max 35 kts wind and max 5 meter swell. His heading of 83 degrees falls in lign with Dalin routing around the heavy stuff. The blue line is routing without wind or wave constraints.

Also, the ETA's to the virtual WP are within 13 hours arrival after Dalin for the chasing 7 boats. Pressure stays on the leader.  

routing table 071220.png

Dalin 071220.png

Burton 071220.png

Dalin 2nd routing avoiding heavy weather 071220.png

 
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littlechay

littlechay

Super Anarchist
1,205
657
Nelson
Bristol-Cruiser said:
I got hit by a flying fish one night and it hurts. Also leaves a fishy smell on your face. My wife was behind the wheel and ducked down for some reason, adjusting the Monitor steering line I think, and a FF passed over just where her face had been. She thought it was quite funny when I got fished, I suspect she would not have seen the humour if she got hit.
Click to expand...
It hurts but you can get revenge by eating them.

 
F

F18 Sailor

Super Anarchist
2,689
265
Annapolis, MD
Herman said:
Weather update + AIS positions

After updating Anaconda Navigator and playing with Python for half a day, I succeeded in running the AIS-script posted up thread earlier and import the positions for the first 8 boats into OpenCPN. Compared the reported 17:30 positions with their AIS-positions. As the timestamps for AIS differ from the 17:30 timestamp and benchmark, there are differences. For some boats these delta's are bigger than I can explain atm. Either the AIS scraping is not accurate enough for some boats, or their reported positions do not match the 17:30 timestamp. My guess is the latter, as AIS does not lie and there are almost no other boats in the area that could trigger a false AIS-report. And AIS speed and heading confirm it's a VG-boat when checking the offical tracker.

DELTA AIS-position versus Reported 17:30 in NM and time:

  • Dalin 9 nm and 35 minutes (seems accurate)
  • Burton 23 nm and 87 minutes (not OK) 
  • Seguin 36 nm and 29 minutes (not OK)
  • Herrmann 48 nm and 88 minutes (not OK)
  • Le Cam 53 nm and 42 minutes (not OK)
  • Bestaven 25 nm and 55 minutes (not OK)
  • Ruyant 18 nm and 51 minutes (seems accurate)
  • Dutreux 24 nm and 35 minutes (not OK)
Click to expand...
General opinion is that the AIS data is more accurate than the official tracker.  At Burton's average 4h speed of 13.9kts, 13.9*87/60 = 20.2 nm, hence 23nm seems reasonable no?

Some of the others are not of course, Dutreux for example would have to be going 36.92 kts to cover 24nm in 35min, maybe his position reports were confused with Sodebo :blink:

 
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L

Laurent

Super Anarchist
2,379
2,089
Houston
Radio interview of Maxime Sorel; it is on the French side of the website, but not the English side. From what he says, it is tough... And regarding problems and failures, when it rains, it pours...

The skipper of V&B-Mayenne was on the radio call this morning; he explains the tough conditions he has encountered in the past few days and how he manages the problems on board.
" I have never seen a sea state like this! It is very hard to sail, the boat slams, then gets off in an overspeed surf. For safety reasons, I preferred to slow down, and reduce sails. RIght now, I have J3 and 2 reefs in the main. Wind is between 20 and 25 knots, with more than 40 knots in the squalls. The sea state is very disorganized, sometimes it gets a little bit better, but right now, it's nuts. There is a very big swell, and if you do not go fast enough, the waves break on the transom. It is not very comfortable, and it is going to continue, unfortunately.

It's tiring, we have had strong winds for 10 days. Last 24 hrs, you can sail at the speed you want to, otherwise you risk to break the boat. According to the forecast, we should get this type of wind for another 3 days. So we have to cope with it; it should get a bit better afterwards.

I have been told that deep South will be gray, cold and humid, and with a large swell, but they did not tell me that the sea state would be that shitty! The wind shift is so brutal between before the front and after the front that, of course, we end up with crossed seas.

I have spent last night to DETUNE the boat, trying to slow down. I had 3 reefs in the main and the J3 and we had surfs at 29 knots... There is not much more to do; once you reduced sails as much as possible, you just suffer. It is very weird, it is a discovery for me. You have to decide between the race, sailing fast, and keep the boat and yourself safe, so you do not break anything but still keep some speed so you do not get caught by the waves, because it is dangerous.

Last night, I did not really sleep; I was ready to jump on the sheets for the squalls. And last evening, at sunset, I decided to change cloth and wash myself; I had to make water and then, impossible to start the engine. I spent 2 hours working on it, trying to understand what was going on. The boats are continuously heeled right now, so you cannot turn on the engine with the normal water intake configuration; on my boat, the water intake is near the propeller shaft, so I am using the "schnorchel" used to fill up the ballast as a water intake for the engine. But since I have been going too fast, some water got into the engine. So I hade to open up the engine to get rid of the water and restart it. While I was working on that, the boat launched on a surf and I got a problem with my hydrogenerator, which is my second source of electricity on board. I lost all hydraulic oil on the port side hydrogenerator. So I had to deal with that as well. I was completely drained. And then the following night, I had to deal with squalls with winds up to 52 knots. I am knackerred. I don't look at boat speed anymore. I am going to bed and I will see later on...

Today, my life is ruled by the weather systems; I am planning maneuvers in so many hours forward, and in the mean time, i try to rest, to eat, and I wait for the next fuck-up to happen... I no longer think in days by instead in tasks on my backlog.
 
littlechay

littlechay

Super Anarchist
1,205
657
Nelson
Herman said:
Yes that is possible. The weather routing plugin can utilize the wind averages and current data from the Climatology plug in. So you can do a weather routing (pro forma) for winds and currents for a certain month using applicable polars. But I don't have time do this this.
Click to expand...
You can download historical data from sites like Meteoblue.

 

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stief

stief

Super Anarchist
8,118
2,442
Sask Canada
Poor Pip, and the others. Now they have to decide whether to stack the watertight emergency container too.

Article C.3.20 (v) of the Class Rules Imoca 2021 v2.2 specifies that the watertight emergency container must be sealed in place.

Article C.3.20 (v) is removed. Therefore the seal can be removed.
Click to expand...
[aside] Only a week after KE's life raft troubles. Didn't know the Class Rules could be changed so quickly.

 
Snowden

Snowden

Super Anarchist
1,236
702
UK
Laurent said:
impossible to start the engine. I spent 2 hours working on it, trying to understand what was going on. The boats are continuously heeled right now, so you cannot turn on the engine with the normal water intake configuration; on my boat, the water intake is near the propeller shaft, so I am using the "schnorchel" used to fill up the ballast as a water intake for the engine
Click to expand...
They moved the intake to the keel on the foilers to avoid this exact problem, didn't they?

 
L

Laurent

Super Anarchist
2,379
2,089
Houston
Herman said:
Weather update + AIS positions

After updating Anaconda Navigator and playing with Python for half a day, I succeeded in running the AIS-script posted up thread earlier and import the positions for the first 8 boats into OpenCPN. Compared the reported 17:30 positions with their AIS-positions. As the timestamps for AIS differ from the 17:30 timestamp and benchmark, there are differences. For some boats these delta's are bigger than I can explain atm. Either the AIS scraping is not accurate enough for some boats, or their reported positions do not match the 17:30 timestamp. My guess is the latter, as AIS does not lie and there are almost no other boats in the area that could trigger a false AIS-report. And AIS speed and heading confirm it's a VG-boat when checking the offical tracker.

DELTA AIS-position versus Reported 17:30 in NM and time:

  • Dalin 9 nm and 35 minutes (seems accurate)
  • Burton 23 nm and 87 minutes (not OK) 
  • Seguin 36 nm and 29 minutes (not OK)
  • Herrmann 48 nm and 88 minutes (not OK)
  • Le Cam 53 nm and 42 minutes (not OK)
  • Bestaven 25 nm and 55 minutes (not OK)
  • Ruyant 18 nm and 51 minutes (seems accurate)
  • Dutreux 24 nm and 35 minutes (not OK)

Now to the weather routing. In the top-8 boats are 3 without a foiler, that is not bad. Conditions (e.g. sea state) have not been ideal for foiling lately. As the sea seems to flatten a bit around 3 meters for Dalin and Ruyant, these foilers should be able to get their extra advantage until the next LP comes in Tuesday. If sailing on the good bow for Ruyant.

I changed the virtual waypoint towards Cape Leeuwin, 70 nm above the AEZ. After 120 East the AEZ moves to the south, so this corner is a natural waypoint. Adjusted polars for Dutreux and Seguin for non-foiling.

ECMWF and GFS align, more or less, as usual. Not guaranteed on a boat level.

Routing table is in pic 1. Rough rides again predicted due to the new wind coing in from the west for most boats. Dalin, Ruyant and Bestaven have very high max winds in the 40s and 50s kts. I can understand that they want to stay out of this in order to keep the boat in one piece. A detour more to the north could be necessary. See pic 3 for routing Dalin with max 35 kts wind and max 5 meter swell. His heading of 83 degrees falls in lign with Dalin routing around the heavy stuff. The blue line is routing without wind or wave constraints.

Also, the ETA's to the virtual WP are within 13 hours arrival after Dalin for the chasing 7 boats. Pressure stays on the leader.  

View attachment 412564

View attachment 412567

View attachment 412568

View attachment 412570
Click to expand...
Thanks Herman!

Am I reading your table right? Are you predicting 6 boats with 1 1/2 hrs at your virtual waypoint, at the corner of the ZEA, East of Cape Leeuwin??? That would be awesome for the interest of the race...

 
Bebmoumoute

Bebmoumoute

Anarchist
539
1,118
Nantes, France
Yoann Richomme usually does a routing live on Mondays, but he has delayed until tomorrow as he is assisting Damien Seguin with the pilot issues tonight.

 
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B

Bristol-Cruiser

Super Anarchist
5,165
1,700
Great Lakes
DVV said:
I like it. Just have to get used
Click to expand...
I am too old for that ... and get off my lawn. You look at something like Endeavour and it is pure boat porn. Forget the practicality and cost, if you want to be practical take an airplane. We were in anchorage in Antigua when a powerboat around 110' came in and anchored and then a J-boat came in and rafted off its 'tender' for the night. Maybe you sleep on the powerboat where there is a/c, who knows. I could not imagine how much a week charter would have been.

image.png

 
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