I personally find the "accelerated air -> depression/slowed air -> pressure" explanation counter-intuitive. The cause and effect seems to be the other way around: the wind is blowing against the sail, the sail blocks the air from escaping, thus air pressure builds up. On the leeward side the sail blocks the air from coming in (the one trapped windward's), thus depression builds up (perhaps then the air from a higher pressure region rushes in, resulting in an accelerated air flow).
Nice explanation, thanks. Only one important matter was missing though. You shouldn't apply backstay without increasing main luff tension because draft in mainsail moves aft which is just the opposite of what we need. First of all is to apply Cunningham tension BEFORE applying more backstay tension.
At 5:28 it says that as the wind speed increases, the apparent wind moves forward. Not quite right, it moves aft. As boat speed increases then the apparent wind moves forward. I think....
Having take a one inch strip off and exactly parallel with the (old) luff, when that snagged on a spreader, I prefer the outside Gybe. Thanks for the tip. I must learn to tolerate testosterone more and rub shoulders with some racers to pick up more of these things.
Before the gybe, sheet the main all the way out. And don't pull it across during the gybe. It won't impact at all. The sail will luff before reaching the end of the sheet and the spreaders, if you are very alee before it swings. When the winds are high, you want spinnaker to fill on the new side before the main swings. This will be the end of broaching on the gybe.
I doubt it would be possible, you would have to see how your sail is attached, but in all honesty, installing one on a sail with an inmast furler will do practically nothing. Those types of sail do not allow much tuning and performance adjustments
Good video but misuses the term 'roach' when he's actually talking generically about the 'leech'. The leech is the aft edge of any sail. Main sails are not usually a perfect triangle and any additional area aft the straight line from the head to the clew is called the roach.
I really like these videos and the punchline of this video is spot on, but there are a couple of BIG AND IMPORTANT ERRORS in this video. (1) The first is his statement that tensioning the backstay on a fractional boat will not increase headstay tension, when in fact it will add a lot of tension to the headstay. This is something that's easy to measure, is related to headstay 'sag', and sailmakers use adjustment in the amount of headstay sag to make jibs more versatile. (2) The second is his statement that tensioning the backstay on a masthead boat will not bend the mast, when in fact how much it'll bend the mast depends on the mast and the backstay adjuster. I'm currently racing on a 37-foot masthead boat that gets about 4 columns (~24 inches) of mastbend when the backstay is on fully and we reduce bend from the maximum by playing the checkstays.
Agree with your first point. We used to go almost block to block on the backstay to take out headstay sag. Fractional rig. Just retuned the rig and don't need it on quite as tight now. Never sailed on a masthead rig.
Great explanation, thank you. It’s hard for me to understand how curving back the mast actually flattens the sails, though, I know that’s what it does. It seems like that would create more of a camber.
To anyone watching this, Please ignore this explanation it is very far off from the true physics of what’s going on, and will not deepen your understanding of driving w/o a rudder. It’s all about how a tightly trimmed mainsail rounds you up into the wind due to the fact that your center of effort has been moved aft, and vice versa with a jib
