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09-07-2011
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I have not sailed in SF Bay, but I understand the currents run strong. This is going to add an additional factor to your rudder positioning, depending on the strength and direction of the current vs the wind, you just have to play with it.
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Current affects the whole boat and doesn't change the boat's heading, unless you are in a whirlpool or shearing current, which typically don't affect your boat for more than a few seconds. 99.9% of the time you wouldn't notice current if you had no shore references.
Current does not affect rudder position when heaving to. It only adds/subtracts from the speed of apparent wind that you are dealing with. The heading change due to "current direction affecting apparent wind direction" when heaving-to is irrelevant to the process of heaving-to and to your success (or not) in achieving a hove-to position.
Regards,
Brad
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Fun fact #2484: In my avatar, that's DavidPM at the helm of my boat.
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09-07-2011
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Quote:
Originally Posted by celenoglu
One question:
If you are trying to heave to withthe jib and main, how can you reef the main after you are succesful?
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You cannot of course. One reefs beforehand while the jib carries the boat to weather and then flops over on the "backed" tack, hard sheets the reefed main, puts the helm up and makes a cupp'a.
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09-07-2011
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Quote:
Originally Posted by Bene505
Current affects the whole boat and doesn't change the boat's heading, unless you are in a whirlpool or shearing current, which typically don't affect your boat for more than a few seconds. 99.9% of the time you wouldn't notice current if you had no shore references.
Current does not affect rudder position when heaving to. It only adds/subtracts from the speed of apparent wind that you are dealing with. The heading change due to "current direction affecting apparent wind direction" when heaving-to is irrelevant to the process of heaving-to and to your success (or not) in achieving a hove-to position.
Regards,
Brad
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Brad, If this were true; then what you're saying is that the same boat with the same wind and the same sail configuration...would heave-with exactly the same rudder positioning..in a 5 knot current as it would in 0 current.....if that is what you're saying, I think we are going to have to agree to disagree..
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Tempest
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09-07-2011
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Quote:
Originally Posted by Tempest
Brad, If this were true; then what you're saying is that the same boat with the same wind and the same sail configuration...would heave-with exactly the same rudder positioning..in a 5 knot current as it would in 0 current.....if that is what you're saying, I think we are going to have to agree to disagree..
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The current will change the course of the boat and maybe even the direction it's pointed in if it's significant compared to wind speed as the apparent wind direction will shift, but rudder position it can't affect.
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09-07-2011
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Quote:
Originally Posted by Tempest
what you're saying is that the same boat with the same wind and the same sail configuration...would heave-with exactly the same rudder positioning..in a 5 knot current as it would in 0 current.
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Brad is correct. Your hypothetical "same boat same wind" situation is ambiguous. Do you mean same apparent wind? If so, then two identical boats with the same configuration experiencing the same wind and moving through the water in the same direction at the same speed would of course heave-to with exactly the same rudder position.
If you mean "same true wind" then the current will create an apparent wind that has to be taken into account.
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09-07-2011
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Surely the rudder position is a function of the physical characteristics of the boat - keel size and position, size of jib and main, and so on. All the current and wind can do is change the course and heading of the boat when heaved to.
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09-07-2011
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Quote:
Originally Posted by MarkSF
Surely the rudder position is a function of the physical characteristics of the boat - keel size and position, size of jib and main, and so on. All the current and wind can do is change the course and heading of the boat when heaved to.
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Sure, and that's exactly my point. If you're in a current, you may have to adjust your rudder position to maintain the proper Hove-to angle to the wind...this could mean centering the rudder as opposed to having it hard over..depending on the angles..
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Tempest
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09-07-2011
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Quote:
Originally Posted by Tempest
Sure, and that's exactly my point. If you're in a current, you may have to adjust your rudder position to maintain the proper Hove-to angle to the wind...this could mean centering the rudder as opposed to having it hard over..depending on the angles..
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No, that is quite wrong.
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Quote:
Originally Posted by Tempest
Sure, and that's exactly my point. If you're in a current, you may have to adjust your rudder position to maintain the proper Hove-to angle to the wind...this could mean centering the rudder as opposed to having it hard over..depending on the angles..
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Again, true wind or apparent? I think sailors generally mean "apparent wind" when they say "wind" except when giving their oh-so-reliable wind speed reports. You can't directly measure true wind, just as you can't directly measure true current.
For the purpose of deciding rudder angle, I don't imagine anybody ever explicitly considers current. They just adjust things so that the apparent wind is coming from where they believe it's supposed to be coming from in order to be properly hove-to. This decision indirectly takes current into account, since current affects apparent wind.
It's important to note that, really, currents don't affect apparent wind enough, most of the time, for it to make a different for heaving-to. If you're in 10 knots of true wind and you have five knots of current, probably you shouldn't be thinking about heaving-to. If you're in 35 knots of wind and have 0.5-1.0 knots of current, then current is probably the last thing on your mind.
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09-07-2011
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Sure Adam, I"ll agree with all of that. The only reason I brought current up, was because the OP, Mark, sails in SF Bay where I understand there are strong currents....does a 5 knot current matter, in 25 knots of apparent wind...? I can't say..it was a " it might be a consideration" comment...
Yes..apparent..is what we sail...
I know, in the Hudson River with up to 5 knots of current, I have to make adjustments to my rudder angle to get the boat to lay the way I want it to sometimes.....it's not simply a matter of putting the rudder hard over...
To your point about, heaving-to in 10 or 15 knots of wind ( A) in a 5 knot current, that's often what I need to do...to demonstate the manuever...
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Tempest
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