transition from displacing to planing

kerschi

New Member
I've just started sailing a Laser. Now I've a question which possibly sounds a little bit strange:

How can I feel the transition from displacing to planing. Is it necessary to notice this transition? When I'm on a broad reach and there is a lot of wind I'm quite sure to plane. But when beating upwind I'm not sure to feel the difference. I suppose that at this transition I probably have to change my trim (e.g. sitting position. ...)

Thanks for any comment,

Markus
 
Hi Markus

You don't have to worry about any transition upwind, the singlehanded Laser stays in displacement mode. As the wind increases, you become overpowered and can not generate enough stability to harness the extra power, so you end up getting rid of the extra power.

Reaching and running, the transition is pretty obvious, you'll discover that heading up from a broad reach to increase power in the sail is enough to move you from displacement to planing and then you'll learn how to steer the boat back down while staying on plane. There are other skills that you will aquire to help pop the hull on plane as well, a well timed pump of the sail, adjusting the vang correctly etc.
 
FWIW, it seems to me that the displacement->planning transition on the Laser is less dramatic than other boats I've sailed (ex. 470). It might just be me, too...

For example, on a 470 it feels like the boat just jumps out of the water and accelerates; the tiller response also suddenly becomes *very* sensitive. I think perhaps the Laser lingers a bit more in the "Forced Mode" between displacement and planning than some other more freely plainning boats:
http://cerebus.winsite.com/archives/2001/msg01449.html
http://cerebus.winsite.com/archives/2001/msg01460.html

Perhaps there's someone out there who sails Lasers and skiffs who can provide some firsthand comments?

BTW, one thing to note in the above articles is their recommendation of Frank Bethwaite's book, "High Performance Sailing". Flat out, if you don't own a copy of this book you should buy it; if you own it and haven't memorized it, you should re-read a section next time you are off the water.

Cheers,

Geoff Sobering
DN US-5156/Laser 145234/Renegade 510
 
Upwind, unless you hike like superman, you will almost never go into planning mode, however off the wind and downwind there are suttle differances that you will notice. sidewise forces on the rudder will change, due to a change in waterflow past the rudder, you can feel this in the tiller and tiller extension. also the flow of water over the daggerboard will change as the hull enters planning mode, both of these effects will change how you steer using you wieght and using the sail when running downwind. But also be aware that if you enter a plane because you are surfing down the front of a wave, the physics of the situation will be differant and the feel will be differant. So in conclusion, it is all about how well tuned you are to your boat and how well you have the boat tuned. Hope that all made sense.
 
On a windy day, the Laser will plane if you point a little below a close-hauled course and hike like mad. in reality you go from displacement, to bow out of the water to planing; with noticable performance improvements at each stage. Watching videos of Lasers training you can clearly see three stages in the displacement to planing transition.

My suggested explanation is:

1) Boat accelerates and overtakes its bow wave ("official" planing definition) - bow lifts out of water.
2) As boat accelerates apparent wind shifts forward (heads) so sails depower.
3) Sailor trims in/bears away and suddenly accelerates.

Things to look for at the transition are:

1) The bow wave out each side leaves the sides of the boat much further back.
2) Wind shifts forwards.
3) Boat accelerates.
4) If you are hiking you can probably see the bow lift if you are sitting forward.
5) Transom wake turbulence decreases.
6) You are moving faster than another Laser.
7) The rest is instinct...

In reality, what you should be focusing on is not "Am I planing, if so, how fast am I going?..." but more like:

"How do I get this boat to go even faster?"

In terms of performance, knowing if you are planing or not does not really improve your race results.

One thing to note is that if your laser is going more than 5kts, then it has to be planing! You can plane and still not go that fast. The trick is to make the transition from slow planing to damn fast planing because anyone can get the flat aft section of the Laser to plane...
 
Great Question!!!!!



Pick up a copy of Laser Coach 2000. The whole thing is packed with big laser names. There is a section were they are off the coast of France somewhere running in 30 plus knots of breeze surfing through 5 foot swell outrunning, literally, a chase boat with a 75hp motor on it full out...... these guys are jybing so fast it would take your head off ..... it's truly an amazing sight to see. I think once you learn the potential of the boat and gain the confidense... speeds in these boats can be amazing.

I find from my own expieriance that when you start planing the whole boat becomes much more sensitive to driver input noticably so...not just a little.... you can literally feel the boat gliding on top of the water...... in heavy wind sometimes all you do is plane when off the wind. It's what i live for when on my boat.....
 
Anybody know of any cool videos of lasers that can be found on the net?
 

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