Tuesday, 16 December 2014

Learning from the mistakes of others

Volvo Ocean Race is setting up an independent inquiry into the Vestas incident in Leg2. See release here

There are a large number of factors to consider in this report. I for one will be very interested to read the outcome from a technical and a human perspective.

A very undesirable outcome of this report may be new rules/legislation to go some way to prevent this from happening again - i.e. creating exclusion zones around land masses, or external/third party intervention.

This is already evident in races that now have restrictions/limits in place for ice, drastically changing the way oceanic races are run. Having experienced the over cautious and at times in my opinion ill conceived constraints placed on long Southern Ocean legs, the last thing adventurous races such as this require is more restrictions.

Also seen is the navigation restrictions placed at some large international regattas preventing well prepared and knowledgeable yachts from taking advantage of their research and knowledge. Les Voiles de St Tropez and some events run by YCCS in Porto Cervo place buoys off of charted but submerged rocks as a reaction to a yacht that had an issue with that rock.

There is a fundamental tenet in yacht racing (or any other navigation) that the safe navigation of a vessel is the sole responsibility of the Captain/Skipper/Person in Charge. When did it become the responsibility of event organisers to legislate against this principle?

If these events (specifically the likes of the VOR, Vendee etc) really want to start regulating how a boat should be safely navigated then they need to take a look at IRPCAS - as many parts of these fundamental rules are broken on a daily basis - just in terms of safe speeds and visibility etc. Place speed restrictions on yachts?

One part of me hopes that this will only serve to let us know what happened and assist us in learning from the disasters of others, and then just get on with it.

Saturday, 6 December 2014

VOR 06/12 0640 - It's not over

The fleet has made it's way to the second band of light airs and clouds, and running simulations from their 0640z positions, it's not over until...


The pressure will remain relentless, with eyes glued to the tracking in Expedition of AIS targets.

Positions show a significant loss by ADOR to the fleet in the last 6 hours as she felt the full force of the suction of the clouds.


ADOR does appear to be due to break free very soon...but will it be soon enough.

Two results present themselves, routing is now to finish as the finish area starts to come into range of higher res grib files...

0640z GFS 0.5 deg res

0640z GEM 0.25 deg res

Which ever solution above pans out it is clear the leading 3 have their own tustle, ALVI unsure who to play with, and the chasing duo/trio approx 24hr behind.

Both routes a very similar pattern, a drag race to the corner.





Wind distribution for the leg to the E tip of Oman:

Thursday, 4 December 2014

VOR 04/12 0040z - Is West Best?

At the 0040z report the fleet have lined themselves up and pointing at the mark...the big question now is who will have the best windspeed and angle to the corner.

Note that this run was from the 0040z position, at the 0340 report it appears MAPF has better pressure in the E...

Results at 0040z:

With a 370nm east-west spread, the big question is who will have the best angle and speed to the corner. The leaders are taking the safe option and covering both sides of the course. Deliberately or are they just sailing their own race? My feeling is a little bit of both.

Below shows the wind distribution for the E and W options. It appears the SCA1 side of the course has a greater distribution of TWA's, but on average higher TWS, the MAPF option shows similar (possibly tighter) angles but of a trend down the TWS scale.

Both charts run with an interpolation of the GFS and GEM 0.25 deg resolution models.



Route and results:


0.25 GEM 0040z
0.25 GFS 0040z


GEM
GFS

Current will be playing a factor in the leg but should be reasonably even across the fleet, potentially the W option with a better axis? Shown with the Ensemble run from ADOR position Blue is the GFS 0.25, Red GEM 0.25.


Video is from ADOR position, Ensemble run showing the two different weather models (GEM slightly more wind?). Displayed weather is the GFS 0.25 only.


Tuesday, 2 December 2014

VOR - 02/11 0640z - buffalo girls???

MAPF has hooked into some pressure...and taken 18nm out of the leaders in the last 6 hr. This does look good for them, however catching up is one thing, overtaking is another...


Only a quick update this morning, both run on 0.25 deg GFS and GEM models

00z GEM
00z GFS
00z GEM
00z GFS

Monday, 1 December 2014

VOR - 01/12 1840z - living in a vacuum

The fleet is well and truly parked, and whoever wriggles out first may well get a bit of a leap - the leading 3 have done well to stick together...the slightest zephyr and one boat can stretch for many, many miles...ADOR has done a good job of wriggling away from TBRU and DFRT

SCA1 gets the award for the highest speed of the sched at a point to point SOG of 4.23kt. Another 100nm of this for the leaders, other more...then have to deal with it all over again before getting to the NE trades.


1840z posreport results
TWS I believe is a 15 min average for the period up to the 1840z report...no surprise seeing the IR sat image from 1830z. MAPF seems dug into the massive and very high cloud more than the others.

1830z IR Sat
MAPF strategy still baffles me a little bit, as I do not see the necessity to get E as they state in their reports "we have to get E at some stage" - really? Why?

Below the 0.25 deg GEM and GFS runs, aligning a little bit in terms of W to E spread.

What has not been factored in here is the potential time allowance that ALVI will be rewarded by the Jury for their attention to VEST. By my reckoning, they were on station for approx 8hr. So, under the scenarios below were the race to finish at the E tip of Oman she would have a good result. Juries have never been reluctant to award generous time allowances for actions such as thiers, and my time estimate only takes into account the time they changed course to head towards the lee of the reef, and when the turned to a N course again.

The final image below is a run with the GFS model, with shading over 6hrs showing the sensitivity of the route - sail at the extents of this shaded area will in theory cost 6 hrs in time to the finish - or about 3%.

Again, the 370nm or so to the finish into the gulf has not been accounted for.

GFS
GEM 
12z GEM
12z GFS
GFS 6hr shading

VOR 01/12 - same old same old

Nothing ground breaking in the 1240z report...except there doesn't seem at this stage any more pressure in the E, nor does it look like there will be.

A few miles lost by ADOR...the furthest N boat however will pick up the pressure first?

There is some pressure coming in from the SE of MAPF, but will it make any difference? I doubt it.



Still no clear picture left or right up the course.

Using 0.25 deg GFS and GEM gribs, the optimal results don't show any potential inversion of the fleet. SCA1 and MAPF duking it out at the back of the fleet.

This is no foregone conclusion, just what the models are saying, and not accounting for speed deltas or boat on boat scenarios. Still 8-10 days left just getting to the E top of Oman, still a lot of very tricky race track from there.



0.25 GFS
0.25 GEM
GEM

GFS
ADOR, 0.25 GEM (red) and GFS (blue)
Video is of the GFS run with 0.25deg resolution...


VOR - 01/12 - To E, or not to E...

The leading pack are still edging their way towards the mark, unsure if MAPF play to the E will ever pay off .

My opinion is that it will not. So that question may finally be answered.

The optimisations and some analysis tells me that in theory they will not recover, however there are still some very light airs zones to go through which can punish those who are not paying attention (or those who find themselves in a completely different weather condition) - just ask SCA...

0640z

ALVI has made a great comeback from thier standing by VEST - Justice? Appears at this stage they made a play for a river of current up the SW side of the Mascarene Plateau...


There is a larger current to deal with across the equator, the W option is able to take a little advantage of this.

The separation of the fleet W-E does not seem to be having a great impact on the routing results - comparing the current deltas to the finish deltas neither side seems to have any great advantage...not great news for MAPF...
GEM result

00z GEM fleet route


















00z GFS fleet route


GFS result
























The GEM ensemble optimisation from the leaders current position clearly shows that there is no especially favoured side of the track...