dorox

I have to say, these PR videos might not help them sail faster, but INEOS do get some credits for outreach.

Scraped from https://www.americascup.com/en/advanced-dashboard This, or from my website.

I've updated my web app with new races data: https://ac36.herokuapp.com/map https://ac36.herokuapp.com/stats_app

I think VMG is calculated using TWA from boat wind instruments. Distance to leader seems to be derived from next mark wind instruments (the buoys are fitted with those). So when there is a wind shift at the leg end, there is such divergence. Also, wind-VMG at the top of the leg isn't perfect because boat is sailing to the mark, not to the wind. Lots of nuances, hard to get it right and simple.

My job here is done: AC web team added plots.

So I'll try do add that later. And there is yaw angle to be derived from heading and GPS, too. There is also wind and course data that I want to plot on the map as well. It is on GitHub in a private repository. I didn't want to make it public after reading T&Cs on the AC website, though. (giggling nervously) We have to be thankful for race committee for publishing so much data: F1 is much more secretive, for example.

On my website I have VMG to the wind direction. The problem is that because wind changes direction, the integrated w-VMG and c-VMG would be different. Even more, integrated w-VMG would be different boat to boat. If you are just looking at race progress, the c-VMG is the way to go. If you want to see distance lost/gained during maneuvers, the w-VMG is the better one. But I might be wrong though. If you click on the slider handle, then you can move it right and left one step at a time with keyboard arrows

CMG is quite simple to add, just one question: should it be derived from wind VMG, or course VMG, or simply the distance sailed from GPS? Re colour gradients: this is doable, but in a form of scatter (colour-coded dots along the boat track)

Update: now all races are available at https://ac36.herokuapp.com/map Thanks to @MaxHugen for boat images. If you zoom in, you should see schematic AC75s drawn to scale.

the data is in UTM format for zone 60S. If I understand correctly, these are x, y coordinates in meters relative to a specific point. Mark data is there too, but is arguably harder to pull out. There is also wind data for buoys and committee boat and race boundaries. You can actually get the leeway angle from the available GPS velocity vector and heading. Alternatively, you can see it for yourself here https://ac36.herokuapp.com/map. The boat heading data is used to rotate the boat icon independently of GPS. So if you zoom in to see the boat icons, you'll notice their heading is not always aligned with GPS track. This is especially pronounced on downwind legs.

I made another web app with boat tracks and data side-by-side. It is better to use it on a PC, because map zoom doesn't seem to work on mobile. https://ac36.herokuapp.com/map So far it has only race 8 from Prada cup. You can scroll the slider at the bottom to change the time and see the race progress. It seems like LR got really unlucky with wind shifts at the last upwind. The boats are shown roughly to scale, but I didn't have a good image for AC75 from above. If someone wants to draw it, it would be really cool. It has to be .png with transparent background.

TWS data for GBR is consistently higher by 1-2 kn. This is comparing to other boats' TWS data, as well as stationary wind instruments on the course (buoys, committee boat, etc.). Hence it is wrong to compare TWS between boat to boat. One can't say GBR was sailing in consistently stronger breeze. VMG/TWS data becomes skewed as a result of TWS data: i.e. GBR would be showing smaller VMG/TWS, because their TWS is higher. The best measure for a boat to boat comparison would be simple VMG.

I hope they'll make an AC simulator game together.

LR data. @X35 GER50, note the wind strength was different between two weeks, so vmg/tws might be better.