Kids, mommy and daddy have something to tell you...
No, just kidding! This is about team racing, and to encourage you to start thinking about the separation you either want to gain from a competitor's boat, or that you want to eliminate between yourself and a competitor.
When you are trying to restrict a competitor from maneuvering, you want to minimize separation. If you are 2' away from a boat, they can't gybe without fouling you. If you are 2' away from a boat to leeward and want to gybe, you are going to need to increase the separation. If you want to prevent that boat from gybing, you don't want to let them increase separation.
Sometimes not enough separation from a boat you are trying to control is dangerous. This week already, I have seen a lot (and fallen victim myself) of fouls where a give way boat gets so close to a right of way boat that it can't keep clear (and that's a definition in the rules so it's italicized). When you're beating, and you're the boat to windward trying to slow down boat you have pinned to leeward (as when doing a pass back), you want to make sure you've got enough separation to not drift into that boat. How much is enough? Depends upon the situation.
When you are in a tacking duel, the boat behind wants to create separation enough to keep tacking to accomplish the purpose of the duel. The behind boat's purpose is often to get to the right of the boat ahead with enough separation to come back at the boat ahead on starboard, and gain starboard tack advantage. Oftentimes the boat behind is motivated to just keep tacking to slow the boat ahead, so that a team mate can sail through. You've lost a tacking duel if the boat ahead is able to close down your separation so that you can no longer tack and are pinned.
A boat behind on a run is trying not to get hooked by a boat ahead. The boat behind wants to maintain enough separation to the boat ahead to be able to engage boats behind without being engaged by the boat ahead.
If you get to a stable combination, you are trying to decrease separation to the finish line! The best route to that is generally not letting any of your pairs get too much separation away from your team.
There are a million examples of this in a team race, and they are all pretty straightforward. You might be trying to increase it, you might be trying to decrease it, or you might be trying to maintain it, but in team racing you want to think a whole whole lot about separation.
Wednesday, October 31, 2018
Monday, October 1, 2018
Trust the process, be patient
This post has been severely edited to make it shorter and better.
When they're learning to walk, babies get frustrated and they cry, but they don't give up. Somewhere deep in their little baby brains, they trust the process. When they fall down, they don't say "screw it, crawling works so well for my needs, I'll just get better at that!"
The sailors among you who are most committed to the process and trust it the most are the ones who will improve the most and get there the fastest.
It's easy to think "ahh, screw it, crawling works out great, I get wherever I need to go, I never fall down, why do I need to learn to walk and go through all that trouble?" From what I see, none of you took that approach as babies. Don't take it now.
Trust the process, falls and frustration and all.
When they're learning to walk, babies get frustrated and they cry, but they don't give up. Somewhere deep in their little baby brains, they trust the process. When they fall down, they don't say "screw it, crawling works so well for my needs, I'll just get better at that!"
The sailors among you who are most committed to the process and trust it the most are the ones who will improve the most and get there the fastest.
It's easy to think "ahh, screw it, crawling works out great, I get wherever I need to go, I never fall down, why do I need to learn to walk and go through all that trouble?" From what I see, none of you took that approach as babies. Don't take it now.
Trust the process, falls and frustration and all.
Monday, September 17, 2018
Who Gains?
It's easy to lead with the results from the weekend, but instead I'd like to lead with the work during the week that went into enabling those results. We had a great week of practice. Early in the week with mostly upper class boats we got a ton of work done on starting (Kate was in the coach boat with me that day), and we kept the heat on starting all week. Tons of tacking and gybing practice, as well as mark roundings, and a bunch of sail trim stuff.
This all resulted in a situation on the river where, for example, even though I was standing on Harvard's dock, I could easily make out a top mark rounding that Caitlin and Luke did just by their technique. It was way better than the boats around and they gained on the boats ahead and stretched on the boats behind. The women's tacks and gybes, relative to the fleets they sailed in, were at a consistently high level, by which I mean some boats sometimes tacked and gybed as well as us at times, but we hit that level more consistently than other teams.
Good work pays off. There is a great saying "an amateur practices until s/he can do it right, but a pro practices until s/he can't do it wrong." I'd like for us to get to the point where we outgrow the ability to do it wrong. Lots more work, but we should all be excited to see the sign posts of progress.
Today's post focuses on relative gains in headers and lifts. If two boats are sailing along, one of them gains in some situations and the other gains in other situations. The most common ones follow as diagrams.
In situation 1, we have Boat L (leeward boat) and Boat W (windward boat). They are even with each other, L being an equal amount forward on W as W is above L.
If we get a header in this situation, the boats will rotate clockwise (since they are sailing on starboard), and as you can easily see, Boat L makes a gain in this situation.
Conversely, if they get lifted, Boat W makes a gain.
Simple enough, right?
Then we go to a situation in which one boat is directly behind the other, as shown by Boats A (Ahead) and Boat B (Behind). This is a situation you would often see exiting a leeward mark or potentially at other points during the race.
So let's give these boats a header and see what happens:
Boat A clearly gains in the header, right? Now lets go back and give them a lift instead.
What I'd like you to do for now is to internalize these scenarios and how they play out, so that you instinctively know how a wind shift is going to affect you relative to the boats around you. Good, effective, fast decision making depends on pattern recognition. These are simple patterns, and they need to become hardwired into your brain. Think about them, flip them over in your mind, ask the coaches about how these work, but eventually they need to become part of your hard drive.
Sunday, September 9, 2018
PBO Week
Today's title will mean nothing to most of you since you weren't there, but it will be how I remember this week most easily so that's what this post is called. This is more of a notes post for myself. Things will get more fleshed out in later posts but these notes will help me remember the week and keep thoughts alive.
We've made a lot of mechanics progress this last week and I feel like some strategic/tactics progress too.
Having seen us in a regatta, starts are a limiter (read about limiters here and in the post before it). Line sighting, downspeed boat handling, boat control, these are all issues.
I wonder about the psychology of the team in practice vs at regattas. From the results I've seen (and results aren't the whole story), the team's results this weekend weren't what I'd have expected. Quite simply, though I don't place judgmental expectations on the team, if I'd been asked to guess what our results would havei been this weekend I'd say most of our events would have wound up around 5th or maybe a bit better or worse. We did that well in only one event. That was surprising. Either my impressions of how well the team is sailing in practice is skewed in some way, or the level of competition is quite a bit higher than expectations, or our team underperformed relative to our sailing level in practices. I'd guess a lot of it is the latter but I don't know. Some of it will just take time to learn. We'll look into that.
Aidan and Lauren did a luff duck in one race today and it made my week. They passed at least 2 boats because of it, I was ecstatic to see them whip the move out, in an appropriate situation, and then execute it well, and then have it pay off big. That was really really cool.
I think we might need to introduce a bit more competition into practices. I think our practices are productive and instructive and well run and they have a ton to recommend them, but I wonder whether we're missing out on competitive situations. Tough saying.
PBO was a really pretty event.
We've made a lot of mechanics progress this last week and I feel like some strategic/tactics progress too.
Having seen us in a regatta, starts are a limiter (read about limiters here and in the post before it). Line sighting, downspeed boat handling, boat control, these are all issues.
I wonder about the psychology of the team in practice vs at regattas. From the results I've seen (and results aren't the whole story), the team's results this weekend weren't what I'd have expected. Quite simply, though I don't place judgmental expectations on the team, if I'd been asked to guess what our results would havei been this weekend I'd say most of our events would have wound up around 5th or maybe a bit better or worse. We did that well in only one event. That was surprising. Either my impressions of how well the team is sailing in practice is skewed in some way, or the level of competition is quite a bit higher than expectations, or our team underperformed relative to our sailing level in practices. I'd guess a lot of it is the latter but I don't know. Some of it will just take time to learn. We'll look into that.
Aidan and Lauren did a luff duck in one race today and it made my week. They passed at least 2 boats because of it, I was ecstatic to see them whip the move out, in an appropriate situation, and then execute it well, and then have it pay off big. That was really really cool.
I think we might need to introduce a bit more competition into practices. I think our practices are productive and instructive and well run and they have a ton to recommend them, but I wonder whether we're missing out on competitive situations. Tough saying.
PBO was a really pretty event.
Thursday, September 6, 2018
FJ tacks and gybes
9/5 practice notes:
Yesterday was a productive day. Being productive is fairly easy in perfect conditions, and we managed to nail that. Hooray us.
Most skippers way oversteer into the FJ tacks in flat water. The boat loses almost no momentum as you turn into the tack in flat water so you don't have to steer fast. Steering into the tack more gently gains windward distance relative to a quicker tack, and allows a good roll and fast exit from the tack.
There is NO preroll in an FJ tack, except in very light air if you are trying to cheat. So there is no preroll in an FJ tack. The skipper's body movement is to slide your butt aft enough to point both knees forward as you turn the boat into the wind, and then give a good solid upper body roll as the jib backs (most were doing this roll way too early yesterday - the best FJ crews will nearly universally say that in light and medium air the roll happens as the jib backs enough to hit the mast, which is way later than most of you are used to rolling), and then cross and flatten.
Crews need to work on footwork in the tacks, as a lot of people got hung up in the straps. It is no crime to look at your feet during every tack for a day to learn what they are doing and how they are interacting with the boat. Your tacks won't be the best during this process but we are investing in learning here. You will be better after this process.
In a proper light/medium wind to wing FJ gybe, the hardest part is not spinning out to windward on the new gybe. If everything is done right in the first steps, it's going to be easy to spin out. But if you manage to avoid spinning out, your gybes will be awesome.
Step 1 is "we're gybing." The crew takes the jib sheet from the skipper and KEEPS THE JIB FLYING. #1 mistake yesterday was everyone just dropped the jib in the beginning of the gybe. That's slow. Board goes some of the way down. Less in an FJ than in a 420, more on this in a later post.
Step 2 is a very very (very) small steer into the gybe, while the crew shifts weight to windward and the full jib helps steer the boat down. Windward heel and a full jib make steering almost unnecessary. The boom is flipped over and the skipper crosses and immediately goes to a pretty aggressive "weight out" position as you turn the boat fairly hard downwind. THIS IS THE MOST RUDDER MOVEMENT OF THE GYBE but it's still not huge. The crew also helps to get the boat heeling to windward as soon as the boom switches sides. You have to get used to the feeling that you are going to spin down into a death roll - that is the correct feeling, you just don't actually do the death roll part.
As the boat is turning down, the crew is already gybing the jib with a very hard pull of the sheet through the block, after which the skipper takes the sheet to wing the jib, board goes back up, and you are off and running.
Other notes:
Most people have too much vang most of the time. Your vang should be slack in pre-start, unless you have an excellent reason otherwise. If you head down with the vang on, you accelerate. Most of the time you are heading down in pre-start, you are trying to pivot to protect your hole. Accelerating screws that up completely.
There is a reason that I will encourage you to sail backward every day. It is not just for show. Boat control on the starting line is VERY IMPORTANT, being able to back the boat is a big part of that but also one of the most effective start line boat position moves is being able to head the boat down from nearly head to wind to close hauled by simply pushing your boom out hard once, quickly. It's a tough move to master, almost no people truly get it (I had it nailed for about 3 years and now don't practice anywhere close to enough so I stink at it), and sailing backward is THE key step in learning it.
Yesterday was a productive day. Being productive is fairly easy in perfect conditions, and we managed to nail that. Hooray us.
Most skippers way oversteer into the FJ tacks in flat water. The boat loses almost no momentum as you turn into the tack in flat water so you don't have to steer fast. Steering into the tack more gently gains windward distance relative to a quicker tack, and allows a good roll and fast exit from the tack.
There is NO preroll in an FJ tack, except in very light air if you are trying to cheat. So there is no preroll in an FJ tack. The skipper's body movement is to slide your butt aft enough to point both knees forward as you turn the boat into the wind, and then give a good solid upper body roll as the jib backs (most were doing this roll way too early yesterday - the best FJ crews will nearly universally say that in light and medium air the roll happens as the jib backs enough to hit the mast, which is way later than most of you are used to rolling), and then cross and flatten.
Crews need to work on footwork in the tacks, as a lot of people got hung up in the straps. It is no crime to look at your feet during every tack for a day to learn what they are doing and how they are interacting with the boat. Your tacks won't be the best during this process but we are investing in learning here. You will be better after this process.
In a proper light/medium wind to wing FJ gybe, the hardest part is not spinning out to windward on the new gybe. If everything is done right in the first steps, it's going to be easy to spin out. But if you manage to avoid spinning out, your gybes will be awesome.
Step 1 is "we're gybing." The crew takes the jib sheet from the skipper and KEEPS THE JIB FLYING. #1 mistake yesterday was everyone just dropped the jib in the beginning of the gybe. That's slow. Board goes some of the way down. Less in an FJ than in a 420, more on this in a later post.
Step 2 is a very very (very) small steer into the gybe, while the crew shifts weight to windward and the full jib helps steer the boat down. Windward heel and a full jib make steering almost unnecessary. The boom is flipped over and the skipper crosses and immediately goes to a pretty aggressive "weight out" position as you turn the boat fairly hard downwind. THIS IS THE MOST RUDDER MOVEMENT OF THE GYBE but it's still not huge. The crew also helps to get the boat heeling to windward as soon as the boom switches sides. You have to get used to the feeling that you are going to spin down into a death roll - that is the correct feeling, you just don't actually do the death roll part.
As the boat is turning down, the crew is already gybing the jib with a very hard pull of the sheet through the block, after which the skipper takes the sheet to wing the jib, board goes back up, and you are off and running.
Other notes:
Most people have too much vang most of the time. Your vang should be slack in pre-start, unless you have an excellent reason otherwise. If you head down with the vang on, you accelerate. Most of the time you are heading down in pre-start, you are trying to pivot to protect your hole. Accelerating screws that up completely.
There is a reason that I will encourage you to sail backward every day. It is not just for show. Boat control on the starting line is VERY IMPORTANT, being able to back the boat is a big part of that but also one of the most effective start line boat position moves is being able to head the boat down from nearly head to wind to close hauled by simply pushing your boom out hard once, quickly. It's a tough move to master, almost no people truly get it (I had it nailed for about 3 years and now don't practice anywhere close to enough so I stink at it), and sailing backward is THE key step in learning it.
Monday, October 2, 2017
J24 sailing late summer/early fall
If any SG kids are still subscribed to this thing, I'm going to use it as my sailing notebook since I've been doing a bunch more sailing of my own lately. You're more than welcome to read it, it may be super helpful, but I'm writing it for myself and I have a tendency to use naughty words when I do that so fair warning. You'll also see crew names but I'm only using last initials at most. This is one of those times where you get to choose to be cool or a jerk in life. If you figure out who someone is and I have a critique of him or her, please keep it to yourself. It's the height of uncool to do otherwise.
J24 Thursday night 8/10
Conditions: Light southerly, slight ebb.
Boat: Buckshot
Crew: Steven drive, Larry trim, Jane mast, Tom K bow, DK tactics
Result: 8, 1 (no clue overall)
Race 1: We had an okay start and good speed and all the right answers on where to go, there was just so much fucking chatter on board that I got drowned out and we fucked up the beat and had to pull an OK top mark rounding out of my socks, then same thing happened on the run and we got neck punched. I almost jumped off the boat, swam in, and re-quit sailing.
Race 2: I asked for a lot less chatter and people were cool about it, we rounded top mark close 3rd, made a fairly ballsy split at a cruise ship, corralled people into one another effectively, launched to a big lead and won easily.
Summary - it seemed easy to win on a quiet boat with good wheels and impossible to win on a chatterbox
J24 40th Anniversary Race 8/11
Conditions: Mealy southerly, very strong ebb
Boat: Buckshot
Crew: Steven drive, Larry trim, Jane mast, Bianca bow, DK tactics.
Race 1 (of 1): Weird port at pin start that was effective, early decision to go left for Ft Adams wall lefty plus get into more current quicker. Maybe more aggressive than would have approached a race in a series but in this race you either won or who cares what you got, so be aggressive. We rounded mark 1 with a nice lead. Ducked the current well out of mark 1 even though it wasn't sailing most toward the mark. Nice gain against boats that gybed early and extended toward the Rose Island current relief.
Larry and I (really Larry) made the call to go west of Gould and that worked. Despite the leeward mark (the green north of 1/2 way rock) being invisible, I had the chart marked so we were able to find it without much drama. The rest of the race was kind of easy and boring. There were no passing lanes and we had good speed. 4 past class world champions (at least) had a shiny spot on their mantle all cleared off for that trophy, but now they get to come look at it anytime they want to.
J24 J/Fest 8/12 and 13
Conditions: No racing Saturday; fog and medium southerly with moderate ebb Sunday
Boat: Buckshot
Crew: Steven drive, Larry trim, John mast, Bianca bow, DK tactics
Race 1 we knew where the mark was because I'd marked the chart and seemingly no other boats had. We had a crap start with okay to good wheels but rounded top mark second because we knew where we were going. Passed the slower lead boat on the run and won.
Race 2 not great start, got pinballed around because who doesn't like to tack on the boat that won the last three races you've sailed, got nearly taken out by A-Salt on the run, grovelled back for 6th.
Race 3 terrible start, got flushed out right, got good pressure immediately and stuck with it, then got the header to make it a superfecta and that game was over. Win.
Race 4 okay to meh start, good speed, terrific play to put the boats we'd passed by gybing away into each other, extended up the last beat into a SUPER dying breeze and game, set, match.
J70 tuning 8/15
Don't pull the main in as hard on a J70 as you would a J24. It's an Etchells with an asym. Change your battens to meet conditions. That's about it.
J24 coaching 9/7&8
See North Facebook videos. Power pointing versus shape pointing. Mast butt forward against lowers to corral headstay and prevent over bend. Traveler up HIGH in J24 when vang sheeting so sheet is on a pure in and out plane. Sail upwind in a full luff when it's super nuking.
J24 Changing of the Colors 9/29 - 10/1
Boat: Bogus
Crew: Mike drive, Will trim, Rachel mast, Dave M bow, DK tactics
Day 1: Light. You can be aggressive when it's light and crazy, but you don't want to invite disaster to your door. Despite carding a 1, 1 I would actually say we were the most conservative of the relevant boats. Yes we won both races but we were also the only boat that never had a look at carding a complete shocker race at any point.
Day 2: What a disaster. We tuned well for big breeze. Race 1 proves that the tactician can't make the upwind cross call because you never see the cross. First over the line but with a scoring penalty. Second race we were over and restarted but choked down a Z flag for being over, then won across the line by a minute by going the right direction at every second, faster than everyone else on the course. Race 3 we pissed away a win by not having the spinnaker sheets properly tied to the sail so we took a 2nd. Race 4 we sailed a fine race in SUPER shifty conditions and were set to tack for the win on the last bit when we discovered there was no weather jib sheet led. Our boat handling SUCKED.
Day 3. Super light race that we sailed ok and got a fourth, just the wrong boat took a super flyer and won. For the first time we are not winning the regatta and the RC calls the event despite building breeze. Guess where the winners were from? Also that crew changing shit that they did on the second day was just absolute BS. But we're the North team so smile and be gracious and swear and curse the whole ride home and get over it.
Further notes: when someone's just yapping at you (a family member at Jfest, Dave M at Changing), maybe saying "(Person) please hold that thought I'm trying hard to concentrate" is a better approach than asking him/her to shut up. EVEN THOUGH WHAT THEY ARE DOING IS F'D UP AND WRONG AND STUPID and they should know that why would you start yapping at someone who's in the middle of a complicated look at winning or losing a race or regatta, it pays to be nice.
J24 Thursday night 8/10
Conditions: Light southerly, slight ebb.
Boat: Buckshot
Crew: Steven drive, Larry trim, Jane mast, Tom K bow, DK tactics
Result: 8, 1 (no clue overall)
Race 1: We had an okay start and good speed and all the right answers on where to go, there was just so much fucking chatter on board that I got drowned out and we fucked up the beat and had to pull an OK top mark rounding out of my socks, then same thing happened on the run and we got neck punched. I almost jumped off the boat, swam in, and re-quit sailing.
Race 2: I asked for a lot less chatter and people were cool about it, we rounded top mark close 3rd, made a fairly ballsy split at a cruise ship, corralled people into one another effectively, launched to a big lead and won easily.
Summary - it seemed easy to win on a quiet boat with good wheels and impossible to win on a chatterbox
J24 40th Anniversary Race 8/11
Conditions: Mealy southerly, very strong ebb
Boat: Buckshot
Crew: Steven drive, Larry trim, Jane mast, Bianca bow, DK tactics.
Race 1 (of 1): Weird port at pin start that was effective, early decision to go left for Ft Adams wall lefty plus get into more current quicker. Maybe more aggressive than would have approached a race in a series but in this race you either won or who cares what you got, so be aggressive. We rounded mark 1 with a nice lead. Ducked the current well out of mark 1 even though it wasn't sailing most toward the mark. Nice gain against boats that gybed early and extended toward the Rose Island current relief.
Larry and I (really Larry) made the call to go west of Gould and that worked. Despite the leeward mark (the green north of 1/2 way rock) being invisible, I had the chart marked so we were able to find it without much drama. The rest of the race was kind of easy and boring. There were no passing lanes and we had good speed. 4 past class world champions (at least) had a shiny spot on their mantle all cleared off for that trophy, but now they get to come look at it anytime they want to.
J24 J/Fest 8/12 and 13
Conditions: No racing Saturday; fog and medium southerly with moderate ebb Sunday
Boat: Buckshot
Crew: Steven drive, Larry trim, John mast, Bianca bow, DK tactics
Race 1 we knew where the mark was because I'd marked the chart and seemingly no other boats had. We had a crap start with okay to good wheels but rounded top mark second because we knew where we were going. Passed the slower lead boat on the run and won.
Race 2 not great start, got pinballed around because who doesn't like to tack on the boat that won the last three races you've sailed, got nearly taken out by A-Salt on the run, grovelled back for 6th.
Race 3 terrible start, got flushed out right, got good pressure immediately and stuck with it, then got the header to make it a superfecta and that game was over. Win.
Race 4 okay to meh start, good speed, terrific play to put the boats we'd passed by gybing away into each other, extended up the last beat into a SUPER dying breeze and game, set, match.
J70 tuning 8/15
Don't pull the main in as hard on a J70 as you would a J24. It's an Etchells with an asym. Change your battens to meet conditions. That's about it.
J24 coaching 9/7&8
See North Facebook videos. Power pointing versus shape pointing. Mast butt forward against lowers to corral headstay and prevent over bend. Traveler up HIGH in J24 when vang sheeting so sheet is on a pure in and out plane. Sail upwind in a full luff when it's super nuking.
J24 Changing of the Colors 9/29 - 10/1
Boat: Bogus
Crew: Mike drive, Will trim, Rachel mast, Dave M bow, DK tactics
Day 1: Light. You can be aggressive when it's light and crazy, but you don't want to invite disaster to your door. Despite carding a 1, 1 I would actually say we were the most conservative of the relevant boats. Yes we won both races but we were also the only boat that never had a look at carding a complete shocker race at any point.
Day 2: What a disaster. We tuned well for big breeze. Race 1 proves that the tactician can't make the upwind cross call because you never see the cross. First over the line but with a scoring penalty. Second race we were over and restarted but choked down a Z flag for being over, then won across the line by a minute by going the right direction at every second, faster than everyone else on the course. Race 3 we pissed away a win by not having the spinnaker sheets properly tied to the sail so we took a 2nd. Race 4 we sailed a fine race in SUPER shifty conditions and were set to tack for the win on the last bit when we discovered there was no weather jib sheet led. Our boat handling SUCKED.
Day 3. Super light race that we sailed ok and got a fourth, just the wrong boat took a super flyer and won. For the first time we are not winning the regatta and the RC calls the event despite building breeze. Guess where the winners were from? Also that crew changing shit that they did on the second day was just absolute BS. But we're the North team so smile and be gracious and swear and curse the whole ride home and get over it.
Further notes: when someone's just yapping at you (a family member at Jfest, Dave M at Changing), maybe saying "(Person) please hold that thought I'm trying hard to concentrate" is a better approach than asking him/her to shut up. EVEN THOUGH WHAT THEY ARE DOING IS F'D UP AND WRONG AND STUPID and they should know that why would you start yapping at someone who's in the middle of a complicated look at winning or losing a race or regatta, it pays to be nice.
Wednesday, August 10, 2016
The Cosine
Haven't had a ton of time to post lately but here's a quick thing you should all know: the cosine.
The cosine curve looks like this:
And it rules your life in sailing, whether you know it or not.
How fast you are getting to someplace (whether that place is a mark or the wind) is a function of your speed and how directly you are pointed at your destination. Your speed multiplied by the cosine of the angle between your heading and the destination is how fast you are getting to the destination.
For example, let's say we are going 10 knots (we're sailing Marstroms today) and we are tacking through 90* (Marstroms can't point very high). That means that our true wind angle (the angle between our heading and the wind's direction) is 45*. The cosine of 45* is .707. That makes our VMG (which is our speed of progress into the wind) 7.07 knots. If we get a 10* wind shift, our VMG is still 7.07 knots.
If the mark is directly upwind, then the speed at which we are heading to the mark is the same as our VMG - 7.07 knots. But if we get a 10* header, then the angle between our heading and the mark becomes 55*, and the cosine of 55* is .573. That reduces our speed to the mark down to .573. Ain't that a kick in the pants? On the other hand, if we get a 10* lift, the angle between our heading and the mark is 35*, and the cosine of 35* is .819. So our closing speed with the mark gets bumped up to 8.19 knots.
This is why I am such a freak about pointing to the mark. You have to have a REALLY good reason to not sail towards your next mark. This is a point on which I will continue to relentlessly hound you.
That is all.
The cosine curve looks like this:
How fast you are getting to someplace (whether that place is a mark or the wind) is a function of your speed and how directly you are pointed at your destination. Your speed multiplied by the cosine of the angle between your heading and the destination is how fast you are getting to the destination.
For example, let's say we are going 10 knots (we're sailing Marstroms today) and we are tacking through 90* (Marstroms can't point very high). That means that our true wind angle (the angle between our heading and the wind's direction) is 45*. The cosine of 45* is .707. That makes our VMG (which is our speed of progress into the wind) 7.07 knots. If we get a 10* wind shift, our VMG is still 7.07 knots.
If the mark is directly upwind, then the speed at which we are heading to the mark is the same as our VMG - 7.07 knots. But if we get a 10* header, then the angle between our heading and the mark becomes 55*, and the cosine of 55* is .573. That reduces our speed to the mark down to .573. Ain't that a kick in the pants? On the other hand, if we get a 10* lift, the angle between our heading and the mark is 35*, and the cosine of 35* is .819. So our closing speed with the mark gets bumped up to 8.19 knots.
This is why I am such a freak about pointing to the mark. You have to have a REALLY good reason to not sail towards your next mark. This is a point on which I will continue to relentlessly hound you.
That is all.
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