Island Time 1,288 Posted February 15, 2021 Share Posted February 15, 2021 Yes, strictly speaking, VMG is wind, VMC is to a mark, - see this 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. Quote Link to post Share on other sites
AJ Oliver 155 Posted February 15, 2021 Share Posted February 15, 2021 This is getting good - keep 'em coming !! So, like Wiki, you would say that VMC stands for "Velocity Made (good on the) Course" ?? (Disclaimer - I do not have a trained eye, nor am I anything more than a recreational sailor.) Esp in Bermuda it surely looked as if ETNZ was sailing both higher upwind, and deeper downwind but the commentators seemed unable to explain it. Quote Link to post Share on other sites
Island Time 1,288 Posted February 15, 2021 Share Posted February 15, 2021 Yup. VMC is really all that matters. The highest average VMC wins the race! Quote Link to post Share on other sites
AJ Oliver 155 Posted February 15, 2021 Share Posted February 15, 2021 11 hours ago, Island Time said: Yup. VMC is really all that matters. The highest average VMC wins the race! Right-o, gotcha - but then why do the commentators only talk about VMG ?? Quote Link to post Share on other sites
Black Panther 1,763 Posted February 15, 2021 Share Posted February 15, 2021 When the courses are upwind/downwind the two become the same. Quote Link to post Share on other sites
Island Time 1,288 Posted February 15, 2021 Share Posted February 15, 2021 3 hours ago, AJ Oliver said: Right-o, gotcha - but then why do the commentators only talk about VMG ?? Because they try to simplify it for the masses. + VMG is usually similar on each tack, and can vary widely for VMC if the course is not directly upwind/downwind... Quote Link to post Share on other sites
Addem 121 Posted February 16, 2021 Share Posted February 16, 2021 3 hours ago, AJ Oliver said: Right-o, gotcha - but then why do the commentators only talk about VMG ?? We all use VMG as a proxy for VmC in the same way we use gas as a proxy for petrol even though it is a liquid. over time language adapts based on convenience or laziness not accuracy. until about 10 minutes ago I’d never heard of VMC. 1 Quote Link to post Share on other sites
Deep Purple 530 Posted February 16, 2021 Share Posted February 16, 2021 On Sunday, with the 25 degree wind shift that happened, VMC would have been meaningless for comparing the boats on opposite tacks Quote Link to post Share on other sites
Fish 0 Posted February 16, 2021 Share Posted February 16, 2021 On 14/02/2021 at 8:10 PM, Jon said: As a Course Marshell I was told at level three there would be racing but no spectator fleet so no stake boats required Haven’t heard officially yet but the levels and plan was set way back last year., but then again the one constant in the a whole event is change. I would have thought that even if racing could be held safely at L3, they wouldn't, purely because of the perception / optics of it. Apparently we aren't supposed to go boating under L3, so for the rich foreigners to be allowed to do it would cause some angst I suspect. Not being able to go boating at L3 was a key driver for me taking up windsurfing, so I can get a water fix and some exercise when the gyms are closed and I can't take the boat out. Quote Link to post Share on other sites
AJ Oliver 155 Posted February 16, 2021 Share Posted February 16, 2021 4 hours ago, Deep Purple said: On Sunday, with the 25 degree wind shift that happened, VMC would have been meaningless for comparing the boats on opposite tacks Respectfully disagree: It is he opposite. With that shift it would be VMG that would be meaningless. VMC is even more important then - tells you the rate to which you are getting to the mark. Someone please correct me if I am mistaken . . . thanks Quote Link to post Share on other sites
Island Time 1,288 Posted February 16, 2021 Share Posted February 16, 2021 5 minutes ago, AJ Oliver said: Respectfully disagree: It is he opposite. With that shift it would be VMG that would be meaningless. VMC is even more important then - tells you the rate to which you are getting to the mark. Someone please correct me if I am mistaken . . . thanks Sort of, certainly if you can lay the mark directly, then VMG is not important, only VMC, which will equal SOG, as you are going there directly. And, even if you cant quite lay the mark, then it gets more complex. Usually you want to be on the lifted tack, but if you cant be (Prada cup is a good example, as boundaries make you tack), then then minimum possible time on the unfavoured tack is required, even if VMC is negative! Its the AVERAGE VMC that matters... Quote Link to post Share on other sites
Deep Purple 530 Posted February 16, 2021 Share Posted February 16, 2021 48 minutes ago, AJ Oliver said: Respectfully disagree: It is he opposite. With that shift it would be VMG that would be meaningless. VMC is even more important then - tells you the rate to which you are getting to the mark. Someone please correct me if I am mistaken . . . thanks Assume the boats are tied around the bottom gate, each boat has the same VMG and will spend the same amount of time on each tack albeit on opposite sides of the course and will therefore arrive at the top mark tied. There is a 20 degree wind shift to the right. On starboard tack you will have a much higher VMC than the port tack boat (until you get near the lay line). So there will be no point in comparing VMC 1 Quote Link to post Share on other sites
Jon 407 Posted February 17, 2021 Share Posted February 17, 2021 22 hours ago, Fish said: I would have thought that even if racing could be held safely at L3, they wouldn't, purely because of the perception / optics of it. Apparently we aren't supposed to go boating under L3, so for the rich foreigners to be allowed to do it would cause some angst I suspect. Not being able to go boating at L3 was a key driver for me taking up windsurfing, so I can get a water fix and some exercise when the gyms are closed and I can't take the boat out. Commercial operators/professionals are still allowed to operate under L3 Sounds like we have 3 more attached to Papatoetoe High Talk from officials is it may go ahead this weekend but the above may change this 1 Quote Link to post Share on other sites
CarpeDiem 521 Posted February 17, 2021 Share Posted February 17, 2021 1 hour ago, Jon said: Commercial operators/professionals are still allowed to operate under L3 But they still have to follow the rules... Staff legally must remain a minimum of 1 metre apart at all times If your business requires close physical contact it can’t operate. If we are still at Level 3, (and possibly Level 2), then I can't see them racing. If Level 3 holds and races are abandoned and unable to be rescheduled, either due to Covid or the AC rules, then we may see LR automatically awarded as winners of the Final. That will be disappointing. Quote Link to post Share on other sites
erice 732 Posted February 17, 2021 Author Share Posted February 17, 2021 so back to level 2 and hopefully racing can soon resume LR were getting pretty filthy over the possibility of a delay https://www.nzherald.co.nz/sport/americas-cup-2021-divide-over-prada-cup-covid-plans-as-luna-rossa-oppose-delay/NMFEYTYJETGYVB7NKNLF2WF26U/ Quote Link to post Share on other sites
erice 732 Posted February 17, 2021 Author Share Posted February 17, 2021 organisers don't want to start racing until aucks back in level 1 more people at viaduct etc. LR pretty firm they don't want to give ben's boat builders any more time for a hail-mary boat change hopefully we're just in level 2 for the 2 days Quote Link to post Share on other sites
Romany 162 Posted February 17, 2021 Share Posted February 17, 2021 i reckon that is fair enuff from Luna Rossa. Get on with it. Quote Link to post Share on other sites
Battgirl 23 Posted February 17, 2021 Share Posted February 17, 2021 I agree get on with the yacht racing and send that British lot home next week. Quote Link to post Share on other sites
waikiore 473 Posted February 17, 2021 Share Posted February 17, 2021 The only issue appears to be the crowd at the viaduct, everything else can carry on, the organisers had a plan in place prior for racing under level 3. In this case Luna Rossa are dead right close Viaduct nonsense and get on with the yachting all other Auckland sailing is back on, and we can go out and spectate on our boats or at home or at clubs in our bubble. What is Grant /ACE up to I wonder- history will point out a few facts about this "series" that even TV has glossed over. Quote Link to post Share on other sites
erice 732 Posted February 17, 2021 Author Share Posted February 17, 2021 To the delight of Luna Rossa, the Prada Cup final will resume tomorrow — although America's Cup organisers have made it clear they aren't happy about it with a stinging statement. https://www.tvnz.co.nz/one-news/sport/other/prada-cup-final-back-but-organisers-lash-luna-rossa-not-putting-nzs-health-first you may have realised by now how much i hate bad journalism how's this America's Cup Events wanted to delay a return to the water until Auckland had moved back to alert level 3 to allow crowds to attend, while challengers of record Luna Rossa remained adamant that racing should continue immediately. https://www.newshub.co.nz/home/america-s-cup-2021/2021/02/america-s-cup-challenger-series-to-resume-racing-this-weekend.html there's no great plan to bring journalism into disrepute there just seems a general laziness to stop it falling there Quote Link to post Share on other sites
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