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benny

Cartwheeling (nose diving)

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raking certainly helps alot to prevent nosediving.

What you did by steering upwind a little when the nose bury's is correct and then bring it back downwind again when the nose lifts or the windward hull starts to lift. There is a technique in this that just takes practice.... and sometimes even with lots of practice it jsut does not work smile.gif

Any reason not to use rake?

cheers !

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Thread resurrection!

I took a newbie mate out for a sail today. Sloop rigged, about 160kg all up, in about 15 knots.

He wasn't so keen on sliding back and snuggling with me on the back beam, so I was having to round up into the wind all the time to keep from submarining the downwind bow.

Then we were about to go down the mine again, on a port tack... with a couple of kids struggling to control their 420 under spinaker on starboard reach, coming down upwind of us. If I rounded up we would have gone straight through them.

Long story short, there's a whole lot of mud on my starboard bow, and my forestay snapped when we went over. I came up under the trampoline and immediately knew that something very bad had happened... the tramp shouldn't be flat on the water in a 5' deep lake :-/

Now I'm trying to read up on ways to keep the bow up. I've had suggestions of pulling more jib on, letting jib off... looking at the (dodgy) video, it looks like we had a heap of mainsail draft, and not much downhaul. I'm still learning how to use the downhaul to control sail shape, but wonder whether pulling more downhaul (and outhaul) on to flatten the sail and bring the draft forward might... uh... make things better or worse or do nothing at all?

I did have a little more baton tension than normal - I'd basically rigged for power, thinking that extra power would be handy with the extra weight on board.

Does raking the mast work to pull the bows up work when sloop rigged?

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I'd think:

1. two up and 160kgs is well over the top, not surprising you went over

2. when the breeze comes up we tend to pull everything in - outhaul, downhaul, luff tension - remember that it you tension the jib luff that'll try to pull the mast upright.

3. with rake on a cat rig you have 5.5m forestays and 5m shrouds when in doubt I'd stick to that

4. not seen anyone else fiddle with batten tension - I don't - just set and forget, leave the battens in and tied all the time, we're out of the cotton sail material now!

5. see note 1

I guess when you lose the rig then the boat will land on one side or the other - you got the short straw.

Glad you survived it all ok.

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As Brittney would sing... oops I did it again :D

Some more submarine action yesterday. Quite a bit of breeze (20 knots + gusts at Ballarat airport, about 15km away, maybe a bit more out on Lake Burrumbeet). Solo (~75kg), so I can't blame my forward hand for being too heavy this time.

I was dipping the bows all day, so I was kinda ready when it went deep the first time. Dropped the mainsheet and recovered.

Second time I was consciously trying to steer through the wind rather than depowering. I rounded up well when the bow dipped, but bore away too soon and sent it down in to the mud. Stepped over the bows when it was beyond recoverable.

It seemed to me that the bows were more prone to diving when I had too much boom lift - traveller too far in, mainsheet eased off. Dropping the traveller further out and sheeting on harder seems to pull the centre of power further aft, lifting the bows.

I rigged with a slightly longer forestay strop than usual (I made up a couple of options when I re-rigged the forestay after the incident a few posts back), so the mast is raked a bit more than I've done before (which also should have pulled the bows up, by my thinking, unless I'm getting a weird interaction with the jib slot). Lots of downhaul and outhaul on the main.

I'd also like to point out that I'm getting plenty of successful sailing in, in between these screwups :p. And I'm deliberately pushing the envelope, seeing where the limits are, so it's inevitable that I'm going to find them sometimes. I'm just very analytical and like to figure out _why_ :-)

Tim

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The photo above shows the front beam flattening, may just be camera angle, or may be that dolphin striker is way to loose, or due for replacement,

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Pretty sure that's just camera angle. My striker is tight and in good nick. But I'll triple check next time I'm rigged and tensioned just to be sure.

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Check that your dolphin striker is tight before stepping the mast.

Maricats nose dive if driven hard on a reach - that is just how it is.

You can reduce it by racking the mast and de powering by flattening the sail. In strong wind you drive the boat as hard as you are game hopefully holding it just off the nosedive then ease off or dump the main, if you bury it sometimes it will recover other times it won’t !!

Drop the traveller down.

On a reach you can sit behind the back beam this greatly increases the leverage to keep the nose up.

Can’t tell from the video but you don’t use forestays to the bows with a jib, the weight needs to be on the forestay in the jib.

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Watch a youtube on Laser sailing.  They are all over the place going downwind.  One I watched, I think it was a Worlds Gold Medal race - they never gybed going downwind always twisting and turning to get the most out of waves.  I think it was in Perth or Fremantle and Tom Slingsby won.

Not disimilar to Maricats - change direction often and whenever you look like you're going to go down a wave into the back of another one - guaranteed sphincter clenchers!

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A new angle to add to this thread.

 

I've been thinking a lot about jib shape and power. I've tended to have my jib luff as tight as a frogs bum. There is significant slack in the forestay when unrigged - a loop of cable at the head or tack. Rigged up, the sail stretches until the forestay takes the load, which pulls a lot of shape into the sail. Pulling on lots of jib sheet tends to pull the leech tight, still with a big belly in the sail. Also with a tendency to luff at relatively low pointing angles, because there's so much draft so far forward in the sail. So, lots of power in the jib, and difficult to release power because it gets flappy.

I think this is what has been driving my bow down the hole.

I raced today (mixed class - solo sloop on my Mari, second time racing in about 20 years 😎) in about 20 knots. Usually that would be serious nosedive risk wind, especially in close proximity of other boats forcing unwanted manoeuvres. And some broad reaching legs that give us all nightmares.

I loosened my jib luff significantly today. Just snug on the forestay. That gave me a much flatter sail, much less power forward. Pulling the jib on harder pulled all shape out of it and really depowered effectively.

MUCH less tendency to bury a bow. Even downwind.

This will require more experimentation. I reckon it might be something that needs changing for different wind conditions - a bit tighter in light air when we want more power? But probably not as tight as I have been using.

I wonder if this is something that needs to be more readily adjustable than retying the jib. Anyone done an adjustable jib halyard or cunningham?

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You have good adjustment in the mainsheet, pull in hard and tight uphill and the forestays will tighten, let off and it loosens. Bit like a backstay adjustment on lead mines.

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Simple solution: When it's blowing 20knots + leave the jib on-shore... unless you're 100kgs or more - in which case hang your arse over the rear beam and go for it...
All 70's plasti-cats have the front beam too far forward to allow 'safe' broad-reaching in 20 knots + and that's just the way it is - as confirmed above...
Sure, tacking is harder without the jib, but the extra power of the jib just isn't needed in those conditions if you're of average weight...
Other solution? Sail a Windrush 14 instead - they're MUCH nicer in scary off-wind conditions...

The Maricat is basically a Hobie 14 Mark 2... much more user-friendly - but still without the front buoyancy it needs  - and that's why the Windrush 14 was so successful - it has a much more forgiving hull shape...

Having said that, the really good skippers know how to sail in these conditions - they have their boats tuned properly with the correct mast rake and their trampolines/platforms TIGHT etc - which considerably reduces 'twist' in the structure - thus preventing pitch-poling in all but severe weather conditions..
PP

 

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On 3/6/2019 at 6:29 AM, knobblyoldjimbo said:

You have good adjustment in the mainsheet, pull in hard and tight uphill and the forestays will tighten, let off and it loosens. Bit like a backstay adjustment on lead mines.

This is true, but once the forestay is tight, it doesn't change length much.

The sail itself is much stretchier.

I had my sail rigged "short", so the luff stretched quite a bit under static rig tension.

Then I tried rigging it longer, so the luff didn't stretch as much under static rig tension.

Tensioning the mainsheet will, of course, add tension to the forestay, but the wire doesn't elongate to any significant extent, so the jib luff doesn't elongate either.

Almost the opposite of mainsail luff tension, I found that a tighter jib luff causes the sail to bag up, and get lots of draft. Looser luff made the jib flatter, which was easier to handle in heavy air.

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On 3/9/2019 at 1:27 PM, Prince Planet said:

Simple solution: When it's blowing 20knots + leave the jib on-shore...

I actually furled the jib when the wind came up, and intended to race cat-rigged.

Milling around before the start... it was awful. Just wouldn't steer.

I actually rounded up into the wind and "parked" in irons in the middle of the lake, walked out the bow, untied the reef, unfurled the jib and reconnected the sheet.

I didn't need the power, but the boat is so much nicer to sail with the jib up. Especially now I know how to depower the jib and keep the bows above the waterline.

I very rarely sail cat-rigged. It's like an entirely different, completely unfamiliar boat. I would quite likely have evolved a different rig setup if I had sailed that way more, and hopefully would have gotten better at tacking without the benefit of a jib to pull me around.

The Hobie states are on at our club this weekend. Looking at some of the boats in the yard (I don't get to look at many beach cats close up) - at least one of the H16s has a jib halyard led down the mast so it can be adjusted on the fly. Of course, their jibs are fully battened, which changes the rules completely, but I must read a bit more about how H16 sailors trim their jibs.

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You should make the effort to attend one of the regattas where the NSW Maricat guys will be. That way you can see what they are doing.

The next best chance, without huge amounts of travel for you, will be the next NSW/ACT State Titles to be held in Canberra in October or early November. 

 

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A Maricat and Hobie 16 are completely different pussycats... there's no point in comparing techniques...
When it's blowing 20 knots+, and you're sailing cat-rigged, you will most likely have to do the 3-point 'reverse-tack' 7 times out of 10  - UNLESS you happen to pick exactly the right moment to throw the cat into a tack, and the swell and or waves help push the bows around.
In very strong winds (20-25knots) you need to be brutal - or the boat will control you, instead of you controlling it...
Above 25 knots it's 'survival' - and personally, it's too scary to be enjoyable...

Anyway, you honestly have to 'crash-tack' in 20knots + which usually involves heavy swell and waves.
The fact that u r caught in irons and the boat won't steer indicates that the boat isn't tuned properly and/or set-up correctly... AND your timing is woefully off...
😛
Surely there are Maricat gurus who can offer some personal advice here... as a Windrush 14 sailor I can only offer general advice...

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Is your sheeting position for the jib right.

You should have about equal tension on leach and foot.

if the leach is light and the foot loose you will have a baggy sail. Rule of thumb is to measure one third up the sail. Draw an imaginary line from there through the leach/foot corner to the deck. That is about where the sheeting position should be.

jib bridle should be 1100, with just small shackles, rack your mast as much as the sail cut will allow, ( the old multicoloured sails don’t allow much), 

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