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A High-Tech AI—is pitch pole in its future?
http://www.hobie.com/au/en/forums/viewtopic.php?f=71&t=20667		 Page 1 of 1
Author:  Chekika [ Sat Feb 06, 2010 6:15 am ]
Post subject:  A High-Tech AI—is pitch pole in its future?
In a recent thread, http://www.hobiecat.com/community/viewtopic.php?f=71&t=20589&start=0, we discussed the merit of the AI hull and amas shapes.

Here is a high-tech kayak trimaran. It is a beautiful boat with some design features similar to the AI.

Image

Image

Limelight is entered, along with a second boat, in the Mar 6 WaterTribe’s Everglade Challenge race along Florida’s southwest coast. The race organizers describe the race as follows.

Quote:
WaterTribe Everglades Challenge:
The Everglades Challenge is an unsupported, expedition style adventure race for kayaks, canoes, and small boats. The distance is roughly 300 nautical miles depending on your course selection. There is a time limit of 8 days or less. Your safety and well being are completely up to you.


I queried the builder, Mark,

Quote:
Chekika: I worry about one thing. The design of the amas is for speed. I worry that in a strong following wind and 2-3' chop, that the boat will have a considerable tendency to pitch pole.

Mark:
Ahhhhhhhhhh don't say that!!!

Actually, we've looked at the numbers and we should be fine.
This new masthead chute is big enough to turn the boat into a kite (or a submarine) in any real breeze. The recommendation is for single digit windspeeds only. I've already made the promise to my wife :-)

The wave piercing yet high volume of the bows has, so far, shown no tendency to bury. Part of the reason is that the boat is so light and the CoE of the sailplan in pretty low. The standard boat is about 70 lbs fully rigged!


It will be interesting...

Keith
Author:  quirkster [ Sat Feb 06, 2010 6:51 am ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
I would be more concerned with the attachment points of the forward Aka's. It appears that the weight of the mast and some sail force will be at the center of the aka with a forestay and aftleading sidestays sharing the majority of the sails forces. Looking at the aka attachment point to the hull I only see two boltheads, I hope I'm wrong or they are really strong. The watertribe is famous for rougher conditions than practice runs I hope it all holds together. I'm sure the designers and builders know this and have go no go criterior.
Author:  timo [ Sun Feb 07, 2010 12:11 am ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
Isn't that a warren light craft? I wonder about the potential for water to accumulate in the cockpit. It would be great to have the hull be a first rate sea kayak, as the warren is and the AI is not, but I wouldn't want to sail with a sprayskirt on. If the warren just doesn't swamp or take water in the cockpit, it would be interesting to know more about the design differences between it and the AI (how the warren stays dry) since the AI does throw so much water in the cockpit. The other downside to the warren is that, while they do advertise trampolines for it, I don't think it looks as conducive to sailing with a companion -- looks like it might be difficult to swap in and out of the cockpit. On the other hand it looks faster and prettier than the AI and has a more interesting sail plan. It is also a light boat in comparison if I remember the stats correctly.
Author:  ChaosDave [ Sun Feb 07, 2010 2:15 am ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
http://www.warrenlightcraft.com/specs15sail.html :wink:

looks pretty quick

http://www.cruisingworld.com/article.jsp?ID=1000079903
Author:  Chekika [ Sun Feb 07, 2010 3:30 am ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
Yeah, the Limelight is definitely a Warren Light Craft. As Dave references, here is their commercial version:

Image

The profile seems to show that the kayak hull bow is rockered and significantly above the ama. This should help prevent digging into waves and pitch poling.

I, personally, can't imagine sailing this in rough seas without a sprayskirt on to seal the cockpit.

Keith
Author:  ChaosDave [ Sun Feb 07, 2010 7:14 am ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
yeh the boat is definitely designed for a wave skirt, otherwise i reckon you would sink this bad boy in any kind of chop.
Author:  ChaosDave [ Sun Feb 07, 2010 7:18 am ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
quirkster wrote:
I would be more concerned with the attachment points of the forward Aka's. It appears that the weight of the mast and some sail force will be at the center of the aka with a forestay and aftleading sidestays sharing the majority of the sails forces. Looking at the aka attachment point to the hull I only see two boltheads, I hope I'm wrong or they are really strong. The watertribe is famous for rougher conditions than practice runs I hope it all holds together. I'm sure the designers and builders know this and have go no go criterior.



the hulls on these boats are 100% carbon fibre so a lot stronger than the plastic AI, but also more than twice as expensive.
Author:  Chekika [ Sat Mar 06, 2010 4:26 pm ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
I went to the start of the WaterTribe Everglades Challenge. In addition to the 2 AI Tandems that were going to be in the race, I was particularly interested in the Warren Lightcraft trimaran sailing kayak show above. When I got to the beach (starting point) on Friday afternoon, Mar 5, many boats were in the final stages of preparation for the start of the race the next morning. Here is a picture of the Warren Lightcraft--it was simply pulled up on the beach as if returning from a sail. All other boats were above the high tide line--the starting point for Saturday's start. No one was around the trimaran for the next few hours. Hummm?
Image

The next morning when I returned at 6:30 am for the 7:00 am start, the trimaran was nowhere in sight. Some bystanders told me that the owner of the boat had sailed it in some chop the previous day (apparently it was quite windy), and when he landed on the beach he was totally frustrated, saying that it was useless for the race since it continually submarined below the waves. I'm not using the colorful words the bystanders told me the owner used. This is all second hand information, but I can verify that the trimaran did not start the race. I was there.

Keith

PS I will report on the 2 Hobie AI tandems that were in the race in a separate thread.
Author:  ChaosDave [ Sat Mar 06, 2010 10:05 pm ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
damn.... maybe he needed a wave deflector :lol:
Author:  timo [ Sun Mar 07, 2010 8:41 pm ]
Post subject:  Re: A High-Tech AI—is pitch pole in its future?
There is a video of some stitched together photos of a TI in the everglades challenge. The TI has a jib rigged somehow.

http://www.watertribe.com/Events/Challe ... eID=EC2010

The bio of the skipper of this boat -- Pelican -- says that the TI is solar powered.
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