How To Practice Sail trim
- Thread starter Don Guillette
- Start date
Andrew: She was a rescue cocker and great sailing dog. Her name was "Shadow" and she followed me everywhere. We have another rescue cocker now. His name is Kirby. He was given that name at the rescue place. There was another cocker at the rescue, who was black like my other dog but my wife said no to that one. His name was "Hoover". Both dogs were given those names because they gobbled up their food like vacuum cleaners!!
Outline:
Sail Trim
1. Draft
A. Factors in determining Depth
B. Factors in determining Position
2. Angle of Attack
A. Determining optimum Angle
B. Compensating for Wind Shear with Twist
Just organizing to keep it simple. BTY: I am a very visual learner, so when I can compartmentalize complex subjects, they are easier to manage, as well as make it easier to understand how they interact.
Sail Trim
1. Draft
A. Factors in determining Depth
B. Factors in determining Position
2. Angle of Attack
A. Determining optimum Angle
B. Compensating for Wind Shear with Twist
Just organizing to keep it simple. BTY: I am a very visual learner, so when I can compartmentalize complex subjects, they are easier to manage, as well as make it easier to understand how they interact.
Well, I guess if you wanted to simplify it even more, you could just reduce it to "Trim". Say what you will, you still have to break the two sub headings (AOA, Draft) down to explain the process. The combination of all four elements result in the optimal trim solution.
not really trying to win an argument as much as just trying to lay it out in simplified format, so their is some hierarchy of focus. this should help knowing why you do what you do. We tend to throw so many things out there, but there is no sequence or priority to the discussion. Instincts from those who are experienced seem to be random choices to everyone else. Creating a outline helps to stay focused on why we make the decisions we make.
Ok, all this talk about organizing and simplification is great, but give us something we can actually put into practice. I have not a Cunningham, a boom Vang nor an out-haul (in spite of the fact I now have a loose footed main) on my 1968 Cal 28. BTW, if anyone has any ideas for adding an out haul to a boom I'm open to suggestions.
Thanks!
Bill
Thanks!
Bill
Bill: Buy the SAIL TRIM CHART and use it to set the controls you do have. In my opinion, once you get over 25' in length and with the size of the sails, you start to need sail trim controls to obtain efficiency from your sails. With smaller boats you can get away with a lack of controls. A cunningham and soft boom vang are easy to add and so is a simple outhaul. Don't forget the controls for the jib. Without the ability to adjust your sails, the fixed setting is fine for one particular point of sail & wind condition and wrong for all others.
I took ASA 101 over the Labor Day weekend d in 2006. The next summer I tried to sail with a crew of one who knew absolutely nothing ab out sailing on my Hunter 216. In 2008 I managed to find a sailor with a Catalina 22. I have been sailing with him since. I think the combination of formal instruction with a patient sailing partner is the answer.
@Will Gilmore:
You look at the shape of the sail. It helps if your sail has draft stripes.
RAther than the concept of "dropping the main", we should think of the concept of "easing the luff tension". He eased the main halyard, which reduced the tension on the luff. Easing the main halyard or easing the cunningham are very similar. They both reduce tension on the luff.
Luff tension controls the forward and aft position of the draft. By easing the luff tension, he moved the position of the max draft aft. A tight halyard pulls the max draft position forward and makes the entry of the sail more rounded. A very forward draft with a rounded entry on a mainsail might be at around 34% of the foot. A looser halyard has the max draft further aft, and the entry is "finer". A "fine" entry would be pointy-er, with the max draft as far aft as 50%.
A rounded entry with the draft relatively forward has a wider groove. It is more tolerant of steering and trimming errors because it is less likely to stall. It works across a wider range of angle of attack. It is better for acceleration, and punching through chop and waves. It's sort of like driving in a lower gear.
A finer entry is faster, but less forgiving.
(BTW, outhaul tension makes a difference in the bottom section of the mainsail. More tension on the foot flattens the foot and moves the draft aft. Full length battens really reduce your ability to shape and move the draft too)
Last edited: