You've answered sum of your questions! The catapult is an awful sensation, after 30yrs of sailing still happens to me, happened to me 3 days ago, had the boom set high, gust came along.... catapult. Lowering the boom helps, longer harness lines, ifya gonna fall better falling backwards than over and onto your gear is better. Instronger winds lower boom, and your weight as outboard as possible.

downhaul your sail more until just before the mast breaks under full load

20/25 knots on a high volume board is going to be difficult to handle, especially if you are just getting into the straps. Going out in 15-20 will help a lot, but I know wind doesn't usually come to order.

How old are your sails and do you have sufficient downhaul on them? Modern sails when set right depower themselves in gusts to a certain extent.

The harness lines should be long enough that your arms are straight when you are hooked in and your hands are shoulder width apart.

Boom around chin height when rigged with mast foot in place.

Harness line position - stand the rigged sail up on the beach. Hold the boom between the harness lines, with one hand. If the back of the sail twists away from you move the lines back a little, and vice versa. When you can support the pull of the sail without it twisting away from you the harness lines are in the right position. To test, hold the loop of the harness line and see if the sail balances.

Have the confidence to lean back. Plenty of weight in the harness is the key to reducing catapults. If you stand upright you lose the weight advantage and you lose mast foot pressure causing the board to bounce around and get out of control.

Bleary said...

what distance from the mast should I have my lines setup?currently I have them @ 40 cm back along the boom.
So lots of down haul flattens the sail also,I was putting a fair bit on,but was worried about breaking something,lots of out haul when windy also?
Cheers for the help.

Harness line position varies with the sail, and how full you have it.
Start with the back harness line about 1/3 of the boom length away from the mast, and lines about 20 - 25 cm apart. As your skill improves you can place them closer together.
Then use my standing the sail up on the beach method above, to tweak the harness line position.
I still do this most times I sail. I find everything much better balanced when I do.

Increase downhaul and out haul when very windy, but beware, you can overdo it, then the sail gets twitchy and really hard to handle. Ask an experienced windsurfer on the beach for advice.

Bleary said...
The problem is,I cannot seem to depower easily when I get a gust,and I end up flying like Biggles.

Don't depower. Especially that stand up, let the back hand out and the mast straighten up type depower. That's a setup for a forward loop. "Sheet in and... whatever you do, don't sheet out.... something something" what's the saying???

Firstly and mostly it sounds like you are overpowered because of the gear. A 6.2 in 20-25 can be a handful, especially if it isn't rigged correctly, with lots of downhaul in this case. That's the major issue here I think. There's just too much force so you can't get going, so the board's dragging, the force and the drag mean over you go. You need to increase that apparent wind angle for comfortable sailing! Everything should feel light!

The thing with windsurfing comfortably is to have the power on tap. You want the sail raked back into the wind shedding a bit or a lot of excess power. The sails are designed to "breath" like this and you'll recognise it when you are "comfortably powered up". In this situation you could stand a little more upright and push the back hand out/forward for a little more power (yes, out) if required in a lull, but you're more likely raked back trying to be slippery. Your weight is comfortably in the harness and you are making finger tip adjustments. There's a huge safety zone between your mast angle and the eye of the wind.

I find the easiest thing to do when suddenly overpowered, from sailing boats actually but it transfers to windsurfing too, is to simply head into the wind. Fast. Try that.

...but once in a while, yeah, you're gonna catapult.

Try keeping your front leg straighter.

I have just lengthened my harness lines and will try to keep front leg straight!
Thanks all for the advice.
Can you get a 5.5 or so that will fit a 430 mast? Most seem to go onto 400 masts it seems.

Bleary said...
I have just lengthened my harness lines and will try to keep front leg straight!
Thanks all for the advice.
Can you get a 5.5 or so that will fit a 430 mast? Most seem to go onto 400 masts it seems.

I have a 5.7 (NP) and a 5.8 (KA) which rig on a 430. I'm sure you'll find a 5.5 which will if you look around a bit. Ring a windsurfing shop. They usually have a big range of sails and are bound to have something to suit.

The good ol catapult.....gone through 2 sails so far

swoosh said...

hardie said...
Lowering the boom helps

I always thought higher boom was better, more righting moment?

I concur swoosh, higher boom = more control, from both a technical and analytic perspective imo

Bleary said...

I do also have a smaller board,it is a 106lt AHD Inspiro,

This is possibly the point, try to use smaller board.,
1.First is teach you proper balance in instant,
2.then will start much easier after each water start
3 Then after few runs on smaller board you will find everything so much easier on bigger board, but you don't want really back unless 120 -130

I can not see any reason for using big boards unless for ultra light winds

CJW said...

swoosh said...

hardie said...
Lowering the boom helps

I always thought higher boom was better, more righting moment?

I concur swoosh, higher boom = more control, from both a technical and analytic perspective imo

Not true guys.
A boom set higher is best in lighter winds as body position is more upright transferring your weight more equally over the entire board which enables flatter board trim affording earlier planing (also pumping onto the plane is much easier with a higher boom). As the wind picks up you need to get your body position lower to increase the leverage. Much greater chance of over balancing and therefore catapulting with a higher boom.
Another way of looking at this is using shorter harness lines in lighter conditions and longer in stronger conditions. I sail adjustable lines on my big gear (8.6 & 7.8 racing blades) and have them set short 28" with boom pretty high. As wind picks up I lengthen to around 32" to 34" and lower the boom slightly. My smaller gear I sail either 30" or 32" lines but my boom is a lot lower.
My 2 cents anyway

Bleary,
Great advice above. In addition, always look upwind and learn to read the water. You will always get visual hints before the gust hits. This visual warning is always a few seconds ahead of the actual gust, just enough time to depower and brace yourself.
Same technique is also useful in marginal winds when you want to get planing. When you see you're going to get a gust, you can turn down wind and ready to apply full power with the gust to get the board on the plane.
Cheers,
YG.

swoosh said...

sausage said...
Not true guys.
A boom set higher is best in lighter winds as body position is more upright transferring your weight more equally over the entire board which enables flatter board trim affording earlier planing (also pumping onto the plane is much easier with a higher boom). As the wind picks up you need to get your body position lower to increase the leverage. Much greater chance of over balancing and therefore catapulting with a higher boom.
Another way of looking at this is using shorter harness lines in lighter conditions and longer in stronger conditions. I sail adjustable lines on my big gear (8.6 & 7.8 racing blades) and have them set short 28" with boom pretty high. As wind picks up I lengthen to around 32" to 34" and lower the boom slightly. My smaller gear I sail either 30" or 32" lines but my boom is a lot lower.
My 2 cents anyway

Fair enough, sounds like you slalom dudes do a heap more tuning than I do. I'm usually a set and forget, and that means chin high boom + 32" lines. How much do you move your boom up and down?

Swoosh,
Probably maximum range of around 10cm from highest setting to lowest although that is across entire range i.e. My lowest posi with the big sails is probably the highest posi with my smaller ones. 5cm either way from the average height - that might not sound much but it has a significant effect on handling. Board width also affects optimum boom position as you'll notice with a formula board the boom is set really high as you sail further outboard than a narrower board.

A positive of using the same model and brand of sail is their consistent height markings on the luff so there's no second guessing.

Guy Cribb cribb sheet is great for setting up lines especially if where you rig is out of the wind.