andyatos
Well-Known Member
On my Laser I've got a couple of sets of tell tales varying distances back from the mast that let me know when I'm starting to get out of trim. On my Sunfish I've got a similar set which work very well when I'm on starboard tack because the flow is not affected by the mast on that tack.
But as we all know, when you're on port tack the mast is creating a disruption of the flow on the leeward side of the sail, which pretty much makes the leeward tell tale on that set useless. I'm curious to hear how you guys deal with this and stay in trim and powered up while pointing.
Here's how I do it. A bit back from the luff just above the top of the mast, I've got another set of tell tails. On port tack, these are in clear flow... because they are above the mast. I do watch these on occasion but because they are way up there, they are a pain to look at with any regularity. Also, if you've got a bit of twist in your sail up there (looser vang, for example) those upper tell tales may show trim where in fact the sail as a whole may be over sheeted a bit.
I also... for super light winds... have a set on the window. So I watch these also when on port tack. These can show attached flow on both tacks... because they are so far back... but because they are so far back from the luff, there may be separation of flow on the leeward side migrating from the upper boom back towards the forward tell tales but you can't see it because your forward tell tales are getting rotored by the mast.
So, for example, when I'm pointing on port tack, I'll scallop my way up wind... meaning I'll slowly head up while watching the leading edge of the sail at the luff where the rings attach the sail to the upper boom until I just begin to see that leading edge start to quiver. That quiver you get just before the luff starts to... well... luff.
As soon as I see this quiver, I'll head off a few degrees... all the while paying attention to my boat speed. Then I'll repeat the process, keeping my boat speed up but while continually testing how high I can go... so that I don't miss a 5-10 degree lefty lift that I could have used but didn't because it wasn't shown on my forward tell tells like it would have had I been on starboard tack and gotten a 5-10 degree righty lift.
Anyway, would love to hear how you all deal with this port tack sail trim issue. Especially when trying to go upwind as fast and as high as possible.
Thanks!
- Andy
But as we all know, when you're on port tack the mast is creating a disruption of the flow on the leeward side of the sail, which pretty much makes the leeward tell tale on that set useless. I'm curious to hear how you guys deal with this and stay in trim and powered up while pointing.
Here's how I do it. A bit back from the luff just above the top of the mast, I've got another set of tell tails. On port tack, these are in clear flow... because they are above the mast. I do watch these on occasion but because they are way up there, they are a pain to look at with any regularity. Also, if you've got a bit of twist in your sail up there (looser vang, for example) those upper tell tales may show trim where in fact the sail as a whole may be over sheeted a bit.
I also... for super light winds... have a set on the window. So I watch these also when on port tack. These can show attached flow on both tacks... because they are so far back... but because they are so far back from the luff, there may be separation of flow on the leeward side migrating from the upper boom back towards the forward tell tales but you can't see it because your forward tell tales are getting rotored by the mast.
So, for example, when I'm pointing on port tack, I'll scallop my way up wind... meaning I'll slowly head up while watching the leading edge of the sail at the luff where the rings attach the sail to the upper boom until I just begin to see that leading edge start to quiver. That quiver you get just before the luff starts to... well... luff.
As soon as I see this quiver, I'll head off a few degrees... all the while paying attention to my boat speed. Then I'll repeat the process, keeping my boat speed up but while continually testing how high I can go... so that I don't miss a 5-10 degree lefty lift that I could have used but didn't because it wasn't shown on my forward tell tells like it would have had I been on starboard tack and gotten a 5-10 degree righty lift.
Anyway, would love to hear how you all deal with this port tack sail trim issue. Especially when trying to go upwind as fast and as high as possible.
Thanks!
- Andy