Hi,
I have a 2008 Gaastra Poison 5.4, the specs are as follows:
Mast - 430
Luff - 434
Base - 4
Boom - 175
I want to make sure I understand how to rig the sail correctly. So from the specs the it appears the mast extension should be set to 40 cm, is that correct? 
Why do they give a size for the base? Because it's a fixed size isn't it?
Cheers,
Ken.
The Luff is how long the sail is from top to bottom. It thusly tells you how long to set your mast.
You have a 430cm mast. The luff is 434. So you set your extension to 4cm. Now your mast is 434cm long.
This extension (or base, but really it's an extension) is set to 20cm:
Boom is self explanatory; set it to 175cm.
Note that when you "downhaul" you pull the sail all the way down to the bottom. Yes really. Keep pulling. No, it won't break. Make sure you are threading the rope correctly and for god's sake don't use anything sharp like a screwdriver to help you. I use the harness hook.
There are hundreds of videos like this on the web. I just picked a random one.
Here's a 2008 Manic rigged, very much the same as a Poison.
The top should be a little floppy, and the two bottom battens should touch the mast a little. There should be some tension at the clew.
The Luff says 434, but don't be afraid to go to 436, as it's sometimes hard to pull the sail all the way down.
How good were 5 batten RAF wave sails!
Select to expand quotebarn said..
Here's a 2008 Manic rigged, very much the same as a Poison.
The top should be a little floppy, and the two bottom battens should touch the mast a little. There should be some tension at the clew.
The Luff says 434, but don't be afraid to go to 436, as it's sometimes hard to pull the sail all the way down.
How good were 5 batten RAF wave sails!
You say the bottom battens should touch the mast a little. Mine usually are about half way around the mast on one side when rigged. Most of the time they stay on that same side even when sailing the opposite direction. It's get the the luff to change sides without making myself fall off, usually by pushing the sail by hand.
Am I doing something wrong?
BTW, I set the mast extension at 7.5cm.
Over time does the luff stretch requiring setting the mast extension longer?
The beginner mistake when rigging is not adding enough downhaul. Having the battens still poking around the mast is exactly what will happen if you don't have enough downhaul.
You need to pull the sail all the way down to the bottom, until it looks like this:
Yes really, all the way down. Use your foot and a downhaul tool that isn't sharp. If you've threaded the line (rope) correctly it shouldn't be too hard.
Don't worry; once you get it you'll get it. It's not rocket surgery. 
You want the top, trailing edge of the sail, the "leech", to go floppy. This makes the sail work as designed. It lets the wind flow.
Here's another video. The internet's an amazing tool for learning.
Select to expand quotewind012 said..
yes .. more downhaul or wrong mast
The mast is a brand new 430 cm, 30% carbon.
Select to expand quoteKennyK said..barn said..
Here's a 2008 Manic rigged, very much the same as a Poison.
The top should be a little floppy, and the two bottom battens should touch the mast a little. There should be some tension at the clew.
How good were 5 batten RAF wave sails!
You say the bottom battens should touch the mast a little. Mine usually are about half way around the mast on one side when rigged. Most of the time they stay on that same side even when sailing the opposite direction. It's get the the luff to change sides without making myself fall off, usually by pushing the sail by hand.
Am I doing something wrong?
BTW, I set the mast extension at 7.5cm.
Over time does the luff stretch requiring setting the mast extension longer?
They can stick further forward, maybe to half way but it depends on your mast. I've used these sails a lot, I had them rigged on 100% Gaastra RDM masts, and also on 60 North SDM's.. We used to have to repair the battens as they rubbed against the mast so much that the battens eventually poked through (incorrect mast)..
But it's not the end of the world, you might need a little more downhaul.
If the sail is not rotating when you're powered up, that's a sign of a problem. If you're only out in 5 knots floating around, you may not have enough power in the sail to pop the battens.
What level are you at? Are you planing around, looking at footstraps and harness?
And you will see in that pic that the pulleys have only made it to about the 4cm mark. So for that extension you'd need to set it at 8cm, not 4 as the sail says.
That is what stuffs people up sometimes, my Chinook extension basically starts at 6cm so I add soem.
Rig to Barn's picture, not to what the numbers say and you'll be right.
Select to expand quoteMark _australia said..
And you will see in that pic that the pulleys have only made it to about the 4cm mark. So for that extension you'd need to set it at 8cm, not 4 as the sail says.
That is what stuffs people up sometimes, my Chinook extension basically starts at 6cm so I add soem.
Rig to Barn's picture, not to what the numbers say and you'll be right.
Ok that's something I would not have picked up if someone had not made mention of it.
I have watched a lot of rigging vids but most don't give enough insight. That's why I had to check about the extension in the first place.
Thanks
Select to expand quotebarn said..KennyK said..barn said..
Here's a 2008 Manic rigged, very much the same as a Poison.
The top should be a little floppy, and the two bottom battens should touch the mast a little. There should be some tension at the clew.
How good were 5 batten RAF wave sails!
You say the bottom battens should touch the mast a little. Mine usually are about half way around the mast on one side when rigged. Most of the time they stay on that same side even when sailing the opposite direction. It's get the the luff to change sides without making myself fall off, usually by pushing the sail by hand.
Am I doing something wrong?
BTW, I set the mast extension at 7.5cm.
Over time does the luff stretch requiring setting the mast extension longer?
They can stick further forward, maybe to half way but it depends on your mast. I've used these sails a lot, I had them rigged on 100% Gaastra RDM masts, and also on 60 North SDM's.. We used to have to repair the battens as they rubbed against the mast so much that the battens eventually poked through (incorrect mast)..
But it's not the end of the world, you might need a little more downhaul.
If the sail is not rotating when you're powered up, that's a sign of a problem. If you're only out in 5 knots floating around, you may not have enough power in the sail to pop the battens.
What level are you at? Are you planing around, looking at footstraps and harness?Select to expand quoteI'm just starting off this is my first sail and I'm using it on my SUP. I aim to wave sail with it when good enough.
I have NO foot straps and no harness, although I have harness lines.
I will try more downhaul next time I go out, had planned to this arv but the wind dropped off.
Thanks for your help.
I have only been windsurfing for a year myself and like you started out with a SUP.
BEWARE- you will enjoy yourself and you will want to go faster. The harness lines are there to help you achieve this. But factory built SUPS are not built to withstand the rigours of overkeen catapulters that are new to this sport.
Get some protection around the nose of your SUP or you will miss out on valuable time on the water over the next few months.
I bought one of Guy Cribbs Cheat Sheets early on. It has the basics of rig tuning on it and is easy to read.
And like a few have pointed out. Getting enough downhaul on will make the difference between an uncomfortable and jerky sail and a comfortable sail.
Got to go we have about 20kts of Sth today so Gybe practice coming up.
