Tacking/Jibing angles

I grew up sailing lasers, thistles and J24s then took about 10+ years away from sailing. I'm back now and loving life in a Hobie 20 but I am having trouble calling the layline or knowing when I can cross someone. Tacking is bad and jibing is even worse. Upwind I know enough not to pinch and keep the speed up. Downwind I work the apparent as much as possible. Any tips as to what to sight through to know what the new heading will look like? And btw no chute on this boat (at least not yet)

Ted,

Tacking: If you can twist on trap and see the mark over your rear shoulder, tack.

Gybing is harder as it is effected by both wind speed and boat speed, assume a gybe angle of about 90 degrees. ie look straight across the boat and then addapt with experiance.

Scarecrow,

we used to estimate that if the mark was at or slightly behind the rear beam, we were on layline to the mark or whatever. This changed a little with different conditions and was based on the Tornado.

Now, how accurate do you jugde the "over the rear shoulder" method to be and was it different for weaker windes when not trapping or in chop? I liked the simplicity of the method so it is nice to know a bit more.

Since neck flexibility is usually restricted (unless you are an owl), it must mean that tacking angle is more than 90 deg

1 of the tasks i have set myself this sailing season is to use my GPS to work out the optimal tack and gybe angles for best VMG

will need to make a waypoint upwind and another downwind, make a route to them, set the display for big digits and VMG, then sail the angles while checking the display

will use the same technique to work out at which wind strength DDW is the fastest way to get home

http://www.youtube.com/watch?v=BNAsxV1ltMU

Different from laser and J24 sailing the speed you can reach with Spi is much higher.
This changes the game to speed over distance.
Look for lift with spi and then go as much down wind as you can without loosing the lift.

Good luck

Click on the Online Store link at the top of this page, buy Rick White's "Catamaran Racing for the 90's". It does a great job of explaining all you need to know about tacking, gybes, etc. as well as boat set up, mast rake, sail trim, etc.

I also grew up racing Lasers, 505's, J-24's, etc. Cats are a whole new ball game, especially downwind. I have found unless the air is very stable, any puff that comes along while going downwind is going to mess up your perfect layline, as you will accelerate and go deeper in the puff, much more so than in any keel boat or even a Laser.

Dead down wind is almost never the faster way to get from the top of the course to the bottom, you are usually better off to head up, heat it up and then bear off as the apparant wind comes foreward.

http://store.catsailor.com/pc/viewPrd.asp?idcategory=99&idproduct=6437

But how high should you fly a hull down wind and how long should you hold it?

It is not about flying a hull. Turning up until the hull flys is usually the biggest mistake I see people make going down wind, becuase their weight is in the wrong place. You will want to turn up untill the boat accelerates (in very light air the acceleration may be very slight, but you will definitely feel an increase in the sheet tension). If it flys a hull before that you are not out far enough or over powered if its windy, if it accelerates without any lift to the hull you are too far out.

.

You can tell if you're gaining or losing space on another boat by lining up their boat with something on your boat (like the forestay or jib window).

How the background moves in relation to your view of the other boat will determine if you are moving faster or slower than they are, and can help decide where to cross their tack.

When in doubt, foot it out.

I use the look over the rear shoulder method for the top mark/layline also. It's not an exact science and your mileage may vary but it's pretty reliable for me.

Hitting the bottom layline is tricky. I try to avoid banging the corners if at all possible and I make my final jibe to the bottom mark fairly close, and I'm using the term 'fairly close' pretty loosely.

Uphill on the H-20, pretty much tack when the mark is at 2:34 or 9:15, not quite square to the beam but close.

Downhill.. .it's ALL about feel. Light-Med is the toughest once it's breezier it sucks for the crew (as me how I know) but the feel is MUCH easier. 15+ I'd say your windward hull should be 3/4 out of the water with just the area around the dagger kissing. Make sure to keep your weight forward on that boat till you get to say 12-15.

[quote=Timbo] Click on the Online Store link at the top of this page, buy Rick White's "Catamaran Racing for the 90's". It does a great job of explaining all you need to know about tacking, gybes, etc. as well as boat set up, mast rake, sail trim, etc.

Got it and read it cover to cover. Nothing specific on the hobie 20 so I compare it to the p19.
If you are on stbd and want to tack to port what do you key on to know you can cross?

At that point it becomes a very specialized skill (errr... talent) that is backed up by the testicular fortitude to push it to the EXTREME last second while being ready to duck if you realize you're not going to make it... and making sure you don't ventilate the rudders and hit the Stbd boat.

If your talking about a opposite tack thing. watch the background. I sail mostly on lakes so this is pretty easy. I think the old saying is if the other boat is eating the trees in the background they'll cross you, if you see new trees emerging from the jib of the other boat you'll cross them.

Something like that ....

Seems like when I had my H-20 I would look forthe mark to be just past the beam to tack for it. Of course that's when the header shows up.