What's Your Top Speed?

Moderator: GreenLake

planeing

Postby Roger » Fri Oct 23, 2009 12:51 am

As a few of you indicate, there is indeed an intermediate mode prior to true planing. It is when the hull is in the process of climbing up the bow wave. This takes tremendous effort, and your placement can actually affect the duration of this transition. To help the boat 'shift gears' you have to move just slightly forward while the boat is climbing the bow wave. This can take only a few seconds if it is occuring during a gust. You know the boat is climbing because you can actually see the bow rise against your horizon. Moving slightly forward, pulls the bottom of the stern out of the water, releaving that little bit of residual drag. At this moment, the character of your wake will change slightly. Its hard to describe, but essentially there is a momentary break in the pattern. The moment that has happened, the boat has successfully climbed up the bow wave, and the stern is no longer dragging. Lift the centerboard slightly to reduce drag further, and as the boat accelerates, sit just slightly back again so the the trim has her riding on the aft most portion of the hull, but without the transom dragging. If the wind is steady, you can hold a plane for a long time. Most times however, you will only get a few minutes. Steering gently to maintain the plane also helps but you really need to be able to read the slight windshifts to do this. A windex helps tremendously.

Planeing is also best accomplished with minimal weight in the boat, so that typically means sailing solo. Now you can see why it is difficult to achieve.... While sailing solo, one eye has to watch the bow rising on the horizon, while the other eye watches for a change in wake pattern. Once on the plane one eye has to maintain as straight a track as possible so that the rudder does not act as a decelerator, and another eye on the mast top windex to ensure that you maintian optimal apparent wind.

To that add one hand to adjust the jib and main, while the second raises the cb slightly..... okay okay... that's pushing it, but it is something like riding a bike... a very delicate balancing act. See this u tube video as an example

http://www.youtube.com/watch?v=QpWrEVGv ... PL&index=3
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Postby mistermoon » Fri Oct 23, 2009 2:52 pm

Sailing solo yesterday in 10 mph winds, I saw 6.5 to 7.0 mph several times if the gps application in my Blackberry is accurate.
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forced mode

Postby K.C. Walker » Sat Oct 24, 2009 4:39 pm

GreenLake,

"Forced mode" is interesting. I suspect that's mostly what I'm experiencing, because it really doesn't feel like windsurfing or waterskiing. It is interesting to me that the boat can get to quite a bit above hull speed (percentagewise) in this mode.

KC
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Postby K.C. Walker » Sat Oct 24, 2009 4:52 pm

J.P.,

I guess the albacores have that power to weight ratio advantage being that they are about half the weight of a Daysailer. It is interesting that they can get up on a plane without using a spinnaker.

I was out Thursday with a friend and we had a nice 15 to 18 kn breeze for a while. Also the swells were about 3 feet with some nice whitecaps. Nothing scary as they were fairly long period waves. They were nice to surf on while on a reach. I kept feeling like we were right on the verge of planing but couldn't quite maintain it. I don't have a spinnaker so I guess that's what I needed, just a little more horsepower.

KC
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Postby K.C. Walker » Sat Oct 24, 2009 5:28 pm

Roger,

LOL! Yes, that video is just what I want to be doing!

When I was out solo couple of weeks ago it seemed like it was faster and closer to planing than the last time I went out with a friend even with more breeze. When I was solo I had to hike out considerably to keep the boat flat where as we were able to do it fairly easily with just sitting on the rail with 2 people. Of course this time the surfing was really good as we had about 3 foot swells.

I was watching the wake quite a bit to try to establish if I was getting up on a plane. This time when I was out most of the time when I was thinking we were getting close to planing the wake crossed pretty close to the transom, like the transom was dragging or like a power boat when it's mushing while trying to get up on the plane (I'll try to get further forward next time). When I was out solo the wake was much flatter and crossed considerably behind the boat like maybe 8 or 10 feet.

Hopefully I'll get another chance to sail this season so I can try your tips. I was just thinking about one of your tips, I think I was pulling the board up too soon because I had to steer too much with the rudder and was probably getting a braking effect. Next time I'll see if I can coordinate that better.

Another thing on that minimal weight problem… I pretty much need to go out with an outboard motor. Having that extra weight hanging off the transom can't help. However, I'm not going out on the big water without a little auxiliary help.

I also think that I need to update my running rigging. I've got mid-boom sheeting that's original and it's quite an effort to deal with when the wind gets up. I think better sheet control would aid trying to get on the plane and keep the boat flat.

Thanks, KC
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Postby K.C. Walker » Sat Oct 24, 2009 5:40 pm

Mistermoon,

It seems to me that a 10 kn breeze is about perfect for comfortable and enjoyable sailing in a Daysailer. I was reading on the Thistle site that they can start to plane in 10 to 12 kn of breeze. Of course, you need 3 people on the rail for that. So I guess we are bit under canvassed for early planing.

It's interesting that you are able to get above hull speed with a moderate breeze. I feel like I zip along pretty well in that kind of breeze myself. Were you sitting on the rail or hiking out?

KC
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Postby mistermoon » Sun Oct 25, 2009 11:25 pm

My top speeds were in statute mph, not knots.

The best speeds were attained on a broad reach. Was the boat planing? Probably not, but the water was coming cleanly off the transom instead of eddying around back there.

To go that fast I'm usually sitting on the rail foward of the mainsheet and hiking as much as I can without hiking straps.

Upwind, I can routinely hit 5.5 statue mph. The boat is a lot faster than I expected, really.
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Postby K.C. Walker » Mon Oct 26, 2009 8:50 am

I found this chart and thought it fit nicely into this thread. :-)
http://books.google.com/books?id=mStJSI ... q=&f=false

KC
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Postby TIM WEBB » Fri Nov 27, 2009 7:55 pm

Just got back from the lake. Took the GPS today. Garmin Etrex Vista CX. I mounted it on a skydiver's chest-mount altimeter pillow that I secured to the top strap of my PFD.

Winds were 10-15 out of the West/Northwest, and a bit gusty. Started out reefed and close hauled, single handed (165 lbs), and managed to hit 7 mph (forgot to change it to knots first, then had my hands too full to figure out how!). Mostly was able to keep it at about 5.5-6 mph average.

Got to the other end of the lake and switched to wing-and-wing to come back, and was making about 4-5 mph in winds that had fallen off to about 8-10.

Next time I'll try to remember to bring my friend's hand-held anemometer, so as to get a better comparison between wind speed and boat speed ...

- Tim
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busting off

Postby dannyb9 » Sun Nov 29, 2009 2:03 pm

there are some kinetics that can be used to help get a boat up on a plane. when heading downwind, if i feel some planing potential, i head up slightly to build some reaching speed and hike hard to keep the boat flat. a heeled boat wont plane. i lean forward while hiked. when the time is right (maybe a downhill from wave action, or a gust) i swing my weight aft and simultaneously bear off , sheeting in slightly as i hold the main to get a burst of power. bust off! then ease the main a little and drive as low as you can without losing speed. keep the boat flat. its easier to keep the boat flat after the plane is initiated. if you feel the boat start to slow, gradually head up and sheet in slightly to keep your speed or repeat as necessary. anyway thats how i do it, it works on many different boats
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Top Speed So Far - 10.9 knots

Postby whitejw1967 » Sat Jan 29, 2011 10:19 am

My friend and I got my 1974 DS II to 10.9 knots on a downwind plane (under full--and new--sails) yesterday. The winds were steady at 15-18 but gusting to 30. We maintained just over ten knots for almost thirty seconds. Recorded by both of our GPS systems.

I'd exceeded hull speed in the 8.5 knot range before but never felt a real 'plane'; the effect was quite noticeable. We shifted weight from mid and forward cockpit to aft as she accelerated and rose and skipped across the water.
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Postby ctenidae » Mon Jan 31, 2011 10:31 am

This thread is already interesting, adn might be even better with the prevalence of GPS systems now.

I've seen 7.8 knots indicated. Going any faster than that I'm usually too focused on not capsizing to read the GPS.
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Re: What's Your Top Speed?

Postby skullersrc » Mon Mar 19, 2018 9:36 pm

After I came in from our sailing club my GPS watch says I hit 11kts on Saturday but I highly doubt that reading. I have definitely seen speeds of 8-9kts on a Broad reach in about 12-15. It's remarkable how quickly these boats pick up speed.
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Re: What's Your Top Speed?

Postby GreenLake » Tue Mar 20, 2018 2:18 pm

Any GPS device that is not fixed to the boat can theoretically give inaccurate readings as the device is moved relative to the boat.

More an issue for a single momentary reading, or something like the peak speed value, not so much if you observe the same number for a bit.
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Re: What's Your Top Speed?

Postby Alan » Tue Mar 20, 2018 2:25 pm

They'll definitely accelerate. I had the pleasure last December of watching a DSI on Morro Bay, beautifully maintained, race-equipped, and in the hands of three very good sailors. It went from a standing start to throwing a bow wave in seconds. They zipped in and out between the boats moored in the channel, coming about so fast that the sails didn't have time to luff, then shooting off in the new direction, again throwing a bow wave. They stayed flat, or very nearly, the whole time. I don't think they were planing; the wind speed at the nearest measuring point I could find online was 8 to 10 knots.
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