Sail Trim

[Askeeta]

Hi All,
Have been getting to know my Sonata7 over the last 6 months, staying on board for a week to 3 weeks at a time
Sailing trim is where l find myself in my learning curve
There are many references to sail trim on the net,could someone please point me to a concise compact reference for me to apply a little more theory to my lacking practice
Thank you

[Alan Mighty]

Originally Posted by Askeeta

Have been getting to know my Sonata7 over the last 6 months, staying on board for a week to 3 weeks at a time
Sailing trim is where l find myself in my learning curve

Have you considered joining the Sonata Yacht Association of Victoria? Members get a password that lets you view the back issues of the SYA newsletter. There you'll find relevant sail trim info.

Have a Captain Cook at: SYA Contacts – Sonata Yacht Association

Here's a partial index of subjects in the back issues of the Newsletter (including one about wind and tides on the Gippsland Lakes):

[danstanford]

Do a search for Don Guillette and find out how to buy his sail trim guide. It is all you will ever need and it is simple to read and understand.
A high level thought to help your own experimentation is that the lower the wind speed the more you need your sails fuller/rounder to make power. As the wind speed increases you will want to make your sails flatter to lower drag. I assume you know to keep your telltales flying and showing the wind is flowing down both sides of the sail when reaching or going up wind.
The next level will be how to shape the sails and what controls do what and then there are subtleties of sail shape and how those telltales should flow which you can learn over time.

[Askeeta]

Originally Posted by danstanford

Do a search for Don Guillette and find out how to buy his sail trim guide. It is all you will ever need and it is simple to read and understand.
A high level thought to help your own experimentation is that the lower the wind speed the more you need your sails fuller/rounder to make power. As the wind speed increases you will want to make your sails flatter to lower drag. I assume you know to keep your telltales flying and showing the wind is flowing down both sides of the sail when reaching or going up wind.
The next level will be how to shape the sails and what controls do what and then there are subtleties of sail shape and how those telltales should flow which you can learn over time.

Thank you,l have seen his name mentioned before

[meirriba]

Excellent book for learning boat trim by Ivar Dedekam -Illustrated Sail & Rig Tuning.
Very good explanations & illustrations.
https://www.amazon.com/Illustrated-S...8326153&sr=8-1

[Stu Jackson]

Originally Posted by danstanford

Do a search for Don Guillette and find out how to buy his sail trim guide. It is all you will ever need and it is simple to read and understand.

https://shop.sailboatowners.com/prod...im-Users-Guide


The best s.t. book ever written, and I've read them all.

[Askeeta]

Thank you all
Just received my book by Don Guillette.
Simple and yet comprehensive,love the quick reference laminated charts
I ended up corresponding with as well,
Thanks again

[Jerry Woodward]

Do you think this book is equally applicable to catamarans or would you recommend something different?

[Askeeta]

Am not an expert,but many of the principles are the same.
On ytube,Caramaran Impi has an interesting technique to close gap between head sail and main to get it to point better
You could ask Don directly,he has been corresponding with me
Yankee3223@juno.com
Cheers

[DanielPerry]

I would use these search terms:

How to power up and power down a mainsail with mainsheet traveler.

How to power up and power down a jib with a jib traveler.

How to reef your sails.

It's simpler than you may be thinking, its all about getting the power in your sails to match and give you a neutral helm (when you let go the helm while under sail the boat goes straight'ish).
First, reef the sails if its windy enough, then get your halyards' tensions right (when its more windy, you need a flatter sail so tighten your halyards), then adjust the travelers to balance the helm. When the jib traveler is moved aft, it opens the leech of the jib and depowers the sail.
When you move the mainsheet traveler to leeward, it depowers the main.

[meirriba]

Originally Posted by DanielPerry

I would use these search terms:

How to power up and power down a mainsail with mainsheet traveler.

How to power up and power down a jib with a jib traveler.

How to reef your sails.

It's simpler than you may be thinking, its all about getting the power in your sails to match and give you a neutral helm (when you let go the helm while under sail the boat goes straight'ish).
First, reef the sails if its windy enough, then get your halyards' tensions right (when its more windy, you need a flatter sail so tighten your halyards), then adjust the travelers to balance the helm. When the jib traveler is moved aft, it opens the leech of the jib and depowers the sail.
When you move the mainsheet traveler to leeward, it depowers the main.

I beg to differ on one point (slightly)
I would deploy the sails to give the boat a very small upwind tendency, something in the order of 2-5 degrees (not more!) and not pure neutral.

[DanielPerry]

Originally Posted by meirriba

I beg to differ on one point (slightly)
I would deploy the sails to give the boat a very small upwind tendency, something in the order of 2-5 degrees (not more!) and not pure neutral.

Great point. do you mean for safety purposes, that the boat tend to round up and luff rather than fall off?

I also meant to add that when trimming sails you generally want to trim them in just until they stop luffing (flapping) and they are smooth. Dont need to sheet in more than this. This will allow you to then move the travelers to balance the helm.

[meirriba]

Originally Posted by DanielPerry

Great point. do you mean for safety purposes, that the boat tend to round up and luff rather than fall off?

This is correct.
Another reason is that in my limited experience as racing helmsman, I find it that the slight pressure on the wheel (or tiller) gives me a better feel of the boat.

[DanielPerry]

Originally Posted by meirriba

This is correct.
Another reason is that in my limited experience as racing helmsman, I find it that the slight pressure on the wheel (or tiller) gives me a better feel of the boat.

Great advice!

[danstanford]

Rudder angled to windward gives more lift to weather.