An inch, really

davidpm · #1 (**permalink**) 08-19-2009

I was main sheet trimmer on a Farr 395 a 40' Farr this evening. This boat has end boom sheeting and a continuous main sheet with a main sheet winch both port and starboard.

I thought I was doing pretty good but a new guy was calling for an ease or trim of an inch.
Does that really make a difference. I couldn't see it especially when he called for the opposite a moment later.

We had very light wind maybe 5 knots.

Was he helping or just showing off?
What is the minimum main sheet trim that will affect performance?

jarcher · #2 (**permalink**) 08-19-2009

I don't know that boat, but very often an inch or so can make difference.

sailak · #3 (**permalink**) 08-19-2009

My boat has a fine-tune for the mainsheet that would allow you to ease or trim a fraction of an inch.

I ain't good enough to use it, still making gross moves.

Someday maybe.

CharlieCobra · #4 (**permalink**) 08-20-2009

When racing? Yeah, an inch can do it. With my baggy sails, a foot is close enough. If I trim down the Genny hard, I still have belly and twist in it so it's a bit of a moot point until I can get fresh rags.

Sailormon6 · #5 (**permalink**) 08-20-2009

When a sail is fairly well-trimmed, there is a point at which all the wrinkles are out of it, and the telltales are flying fairly well, and any further adjustments don't change the overall appearance of the sail to any appreciable extent, but that doesn't mean that the sail's power or performance can't be affected by slight changes in the controls, especially in light air. The reason why most people find it so difficult to sail in light air is because you have to trim the sails as perfectly as possible. Because the wind is so light, the telltales and woolies and vane don't behave normally, so you don't have the usual indicators to help you trim the sails. You can't afford to waste any of the available wisps of moving air through imperfect sail trim, and you have to try to find that perfect sail trim by trial and error. A good racing skipper might ask for a sheet or outhaul to be eased by an inch to generate a little more power to drive the boat through a slight chop or through a boat wake. The fact that the adjustment is so slight that it doesn't noticeably change the shape of the sail doesn't mean that the adjustment doesn't have any effect.

When you're crewing on another person's boat, always trust that the skipper or sail trimmer knows the boat and sails better than you do, and give him whatever sail trim he requests, whether you agree with it or not. The only way you can change his thinking about sail trim is by demonstrating your knowledge whenever you have an opportunity, and that is only likely to happen after many races with him.

Saildoggie · #6 (**permalink**) 08-20-2009

Makes a difference for sure, I race on a Farr 40 occasionally as well as an Andrews 42, an inch makes a difference on the mainsheet for sure.

I normally trim the headsail, an inch is a bunch on that one, a half inch is sometimes eased or trimmed in.

paulk · #7 (**permalink**) 08-23-2009

Sounds to me like the helmsman was asking you to adjust to puffs and changes in heading. With just an inch of change in such light air, it might make sense not to cleat the main sheet but to hold it and play it like a spinnaker. If it's faster than the alternative, it's hard to argue.

sailhog · #8 (**permalink**) 08-23-2009

With end boom sheeting, I say he was messing with you. That's my guess....

CalebD · #9 (**permalink**) 08-23-2009

David,
If this was a race then yes, an inch can make a difference or not. If you were just out sailing then the guy asking for an inch of trim thought that he was racing and needed to get every inch of speed out of the boat.
I have been sailing on a few Sunfish this summer and the angle of the boom can and does make a small difference in the speed of the hull.
If you were just out for a sail then he was likely just showing off.
There is a difference between racing and cruising styles of sailing and the non stop adjustments of racers can easily grate on the more easy going cruisers nerves.
I still like just sailing but we do race our old T27 scow as well.
There are many ways to float a boat; both tight and loose.
See you soon I hope.

mccary · #10 (**permalink**) 08-23-2009

I recall Dennis Connor's main sheet trimmer for the last 12M AC saying that even the America's Cup boats are trimmer correctly only a small percentage time, maybe 10%. So, I am sure that an inch might be the difference between correct sail trim and out of trim. My question is could he duplicate that trim position again without any marks.