I didn't say that you're not a sailor, but the point was that bringing in definitions from another activity doesn't mean that the definition is correct in sailing. The fact that a word means one thing in aviation doesn't mean that it has the same meaning in sailing, "boom" being just one obvious example.

While there are different uses of the term VMG, the most widespread one does seem to use wind as the measure. Even your own source in your earlier post said that velocity made good towards a mark or waypoint is "often more precisely called VMC (Velocity Made on Course)". So the source you bring up says that VMC is a better term for what you were doing. Why, then, do you get narked with those who use it?

Stan Honey, in that article, wrote "A common offshore strategy is to maximize your boatspeed to that next “mark.” We call this velocity made good to course (VMC)." So he was clearly referring to maximising boatspeed to the mark as VMC, not VMG. What Hoskins is descrbing in the Bodacious interview is what is normally called VMC. There's not the tiniest bit of evidence that John would say that it is the same as VMG and he didn't say it was. I can't find any reference to VMG in Connor's first two books. Where is it?

As far as other definitions, are major yacht instrument makers wrong in their definitions where they clearly and specifically differentiate VMG and VMC???
From B & G;

"VMC
A measure of speed towards a specific Mark or target, gives actual progress towards a specific point on a course. Often referred to as "VMG to Waypoint". If you see "VMG" on a GPS unit, it is really VMC.
VMG
A measure of your speed towards the wind. A boat sailing at 90 degrees to the wind has a VMG of zero, a boat sailing at 45 degrees to the wind at 10 knots Boat Speed has a VMG of just over 7 knots."

From Ockam;

"VMG is the Velocity Made Good along the direction of the wind. VMG is a positive quantity going upwind and a negative quantity going downwind."

"VMC is the Velocity Made good on Course towards a mark, a waypoint or any other destination. From a vector point of view, VMC is the component of boatspeed which measures progress directly toward or away from your destination......DO NOT CONFUSE VMC WITH VMG! The only time they are the same is when the bearing to the mark and the direction of the wind happen to be identical. Only then is VMC equal to VMG."

That's Ockam's capitalisation of "do not confuse VMC with VMG", by the way. It comes from their chapter on VMC, which is a completely different chapter to the one on VMG.

Re "and I have won trophies"

At what level and system? For example, winning under PHS has absolutely nothing to do with sailing well.

If by saying you've won trophies you mean you must be correct about definitions, which seems to be the implication, then would you admit that people who have won more trophies and at higher level are "more correct"? Or does winning trophies mean that you are correct, but others who win trophies are not correct? How does it all work?

brady said..
This is an awesome topic - thanks all contributors. A lot of wisdom and experience on display.

I sail a B14 skiff, where instruments are illegal during competiton. But for a while I've been contemplating having some instrumentation I can attach during training sessions so I can really get a better understanding of my best downwind angles (absolutely the key in these things). I'm in a rural area and frequently do not have any similar style boats to compare myself to. Does anyone have any suggestions for something easily mountable/removable, able to get solidly drowned in the inevitable high-speed stacks, and still pretty cheap? Not much to ask really...

Brady,

The simplest and cheapest thing to do , is to record the session on a device you already own that has GPS and then look at the data post session. At the moment, my webapplication will accept any GPX or Garmin FIT recording that you want to manually upload into it, and gives you data based on your best gybe or best tacks, which at their heart are the highest VMG numbers out of all tacks / gybes, and your Polar graph is corrected to these figures. I'm playing with some of the output files this week, and expect them to be in the webapp this weekend version 6.0

Here is an example of what the automatic data you can get looks like - end of session data ( not released verion 5.1 ).

shaggybaxter said..
Hi Dachopper,
I was reviewing your dashboard and just wanted to say.. well done!
I'm seeing a lot of 'Vibe coding' at the moment where people are using AI to generate dashboards of all sorts of stuff, like business performance dashboards, system monitoring dashboards, logistics dashboards to name a few.
AI is getting so good it has this propensity to generate a ridiculous amount of cool numbers, counters and graphs. Whilst this might be uber cool for a sys admin, this is far more likely to be a negative for the large majority of users, as it simply overloads your ability to digest.
I can see a lot of thought has gone into your dashboard to parse all of the noise and try and present useful and informative information.
Full credit to you mate, nice work.

One observation, just something that jumped off the page at me.
In the 'Best Tack and Best Gybe' section, I noted T7 was the best tack. The my brain went straight to "Hmmm. I wonder what were my Best 5 tacks? Were they all around T7? Were they completely random tacks? Were they all on the right hand side?"

I would find useful a Top 5 list of gybes/tacks. That would be a cool data set to have.
(Apologies if you do already and I'm just ignorant.)

Thanks Shaggy,

It has been an up mountain battle!
I've just uploaded sailracerpro.com 6.0 , probably 6.1 by end of today, and updated all linked Garmin watch apps to support.
However Garmin and Microsoft Servers are down for some odd reason.
I added auto-emailing of the session sumamry as soon as the website recieves it from the watch, but maybe another couple days for the servers to get fixed - everything looks ok on my end.

Hours of iterations to get the displays right for sailing !
There is a seperate one for kitesurf aimed at jumping, and I was thinking about parawinging but I'm not sure what info those guys are after exactly.

If you click on the sumamry card - it takes you to the Tack analysis sheet and cues up the replay at the selected Tack. At the moment, the view order is the replay order it occured in ( for tack analysis ) ,


but I also have a Data tab, which ranks all the tacks in order of best to worst, clicking syncs the replay

... also has a shape and grid view of the tack where you can go down the best -> worst list.


finally, I did a few tweeks to the summary colours also, Gold for PB, white otherwise.