Wednesday, 4 March 2015

Caribbean 600 - SORCHA

Charging around the Caribbean...

Raced the 2015 RORC Caribbean 600 on the recently modified TP52 SORCHA. A fun project with a great bunch of guys.

We had a sensational battle with the highly successful Tonnerre racing team, with their new Ker 51 fresh from a win at Key West Race Week. Having a very similar typeform boat, albeit with the Ker 51 being more IRC oriented, made the race for us and pushed us harder and generated a great deal of team focus.

The highlight of the race was possibly one of the best days of racing I've ever had, running in 20-22 kts and a gybing duel with Tonnerre as we neared the bottom of the run...

Expedition track of the run with winds

The lead changed no fewer than 5 times in the race, with SORCHA cementing a lead in the transition through the lee of Guadeloupe.

Track w/winds through Guadeloupe, winds 1km resolution from Predict Wind

Great result

As the chafe and sleep deprivation fade, the satisfaction of an overall 2nd place in IRC, 2nd in IRC zero and CSA made the hard work worth while.

World class crew

Monday, 16 February 2015

VOR 1602 - back to the grindsotone

The excitement is over, get back to work

Seems TBRU have decided to cash in and step back in line with the fleet. Fully understandable and ultimately a smart move as could have been too easy to get greedy and come home with nothing.

They now have a handy ~67nm lead over ADOR, but makes it bloody boring for the rest of us armchair critics now. I was genuinely excited when TBRU and SCA1 stepped up a week ago.

The 1855 posreport references to a fictitious mark again, approx where the routing takes the fleet, however DTF is now approx the same as it is to AKL. Of note is the loss in the last 6hr to ADOR, due to reported less pressure and a 10deg finer TWA.

Optimal route options

Todays run with the 12z GFS at 0.25d shows a far narrower finish margin than when the gauge across the fleet was significant. Back to a dogfight and an AIS interrogation. Must be just like playing the VOR game for the navigator...

Route is pretty straight forward, however I feel will not be as simple as it looks...there are some serious disturbances in the region from approx 5n to 23s, and still looking like a very light ~1000nm to get across before tight reaching into Aotearoa.

The route has a 3hr time sensitivity shaded, quite a narrow corridor which will not do anything for the excitement for us over the next 2 weeks...

ITCZ doesn't look like much now...but the first bank of tropical cloud is less than 300nm in front of the fleet...

Finally, a video of the run...

Saturday, 14 February 2015

VOR 1402 - All that investment and the market collapses?

Buffalo girls on fire?

Although the majority of the massive loss in taking the high road has been recovered and projections still show a net gain, is it enough to bank it at this stage?

The future may go from sound investment strategies to pure gambling.

Posreport from 1855

To a fictitious mark at 50 50n 160e...chosen as the routing suggests this is where the boats will get to, TBRU are in better shape that the VOR tracker suggests.

To route wpt

...or to Dai Island (below) ranking, is of no real consequence, but still a TBRU gain on the fleet (8-10nm in the last 6 hr), and almost a knot faster than SCA1.

To Dai Island wpt

On fire: slightly lighter in the N, but a far better angle (~TWA100 for TBRU, ~TWA65 for ADOR). Nearly a 1kt advantage in VMC.

My polar suggests that the speed deltas should be far greater than they are showing here.

Get the dice out.

Without too much research, it looks like the doldrums are going to be a significant hurdle, GFS models suggesting that there may be as much as 1000nm of sub 10 kt winds to traverse. So what? you may ask, but in these long range lighter airs, a knot of extra TWS in sub 10 is a far more significant delta c.f. 20kt. Someone hooks into a click of pressure and they are off.

Disclaimer: GFS model may not be handling this area very well, and it is over a week away...

So, ignoring for now the chaos of the doldrums, TRBU still come out on top.

The route:

Pretty Dull? The video shows pretty clearly the light airs zone from approx 0:30 (just S of the equator) to approx 1:00. I'll bet the navs are scratching their heads now and possibly starting to manage expectations...

Friday, 13 February 2015

VOR 1302 - diminished returns, but still a return

Evolving weather, changing strategies

0640z posreport, to mark off of Solomons
Report after report still showing losses in terms of DTF by TBRU and SCA1.

Do not think that all is lost. There are still benefits in the E, hence why the fleet is working hard to get out there.

Interesting to note that the gauge continues to increase, albeit not at the rate that the routing has been suggesting.

TBRU and SCA1 have been sailing lower than earlier optimisations propose, the fleet higher. Are TBRU and SCA1 getting the jitters, feeling a little exposed and want to consolidate or get back in touch? Is the fleet still trying to get E to mitigate future potential losses?

History, is it helpful?

Looking at the separation, who would win if they were this far apart at the same time and place 10 years ago? Looking at reanalysed winds from the last 11 years (could go up to 39 but smoke would be coming out my machine).

Reanalysis data is ECMWF.

Pic to the right - green routes are from TBRU pos, red ADOR. Runs are at 0640z on 13/02 2004, 2005,...,2014. '07 and '09 have been deleted for a variety of reasons.

Looking at the results below:

-2004 - TBRU win
-2005 - TBRU win
-2006 - ADOR win
-2008 - TBRU win
-2010 - ADOR win
-2011 - ADOR win
-2012 - ADOR win
-2013 - TBRU win
-2014 - ADOR win

The finish time deltas are in hours only.

Conclusion? Very roughly, and more opinion than anything else, even with the DTF deficit the NE/E route is generally the winner. So, anyones game from here.

Optimisation 0640z

With the GEM 10 day model now covering the majority of the leg, can start to compare against the GFS. The GFS model covers the entire route. GEM wind is extended in time beyond the last time stamp in the model.
GFS 0.5 deg
GEM 0.5 deg

And the routes themselves:
GFS routes
GEM routes

Thursday, 12 February 2015

VOR 1202 - patience, patience

The 1840z report...losses, but still long term gains?

Results from the previous 6 hr - still with TBRU as reference boat and to a WPT off the Solomon islands.

Gains are still there but different

The 1840z Expedition run results to the Hen & Chicks
1840z pos, 0.5d GFS, no current

The round the outside route no longer delivers the anticipated gains prior to the doldrums as seen in earlier runs where SCA1 and TBRU pressed down onto the line of the fleet before entering the doldrums.

They may still elect to consolidate at the cost of some (theoretical) lead and try to get between the fleet and the finish. 

Routing suggests a 250nm W to E separation entering the ITCZ. Allegedly a further E crossing can be less painful, however that kind of leverage in those conditions may be a bit stressful...but it is 10 days away and sat imagery will start to paint a picture of what to expect...

VOR 1202 - turning it inside out

Overnight moving and shaking

TBRU and SCA1 are on their bikes! Looking at the 0640z posreport, to a mark off the Solomons:
0640z posreport
As the projected leg winner at this stage, TBRU are the reference boat so gains/losses and ranges/bearings are from her.

TBRU and SCA1 are ~30nm behind in distance to mark, which I expect to increase over the next 48hr.

In the preceding 6hrs TBRU and SCA1 gained 16nm on the fleet in terms of distance to the mark (VMC).

TBRU and SCA1 covered ~60nm more and reported TWS 17-18kt @ TWD 020-025, so ~TWA 75-80.

The 'fleet' had TWS 13-15, TWD 35-45, ~TWA dead maggot.

Routing to the Hen & Chicks

On a report to report basis the gains from the N route are improving. Depending on how twitchy the skippers are getting (possibly out of the hands of the navigators), the gauge may increase. Routing suggests the fleet should be heading S of E, whereas SCA1 and TBRU do not start getting any S in until 08z tomorrow.
GFS & Tidetech
Overall route

Current not such a major factor now, but still worth +24nm/day. Currents at 0640z from

Wishing VOR would give me posreports every 3 hours!

Wednesday, 11 February 2015

VOR 1102 - so, it appears that it might pay...

Running routes from the 1240z posreport, it looks like SCA1 and TBRU's investment to the N/NE may pay out.

Pictures paint a thousand words

Run using 0.5d GFS at 6hr time stamps, fleet routing from the 1240z posreport in Expedition and Tidetech current info:

1240z GFS run to the Hen and Chickens

Tidetech current info at 1240z

The route

A video of TBRU and SCA1 making their way down onto the fleets line: