AI Tandem: Observations and thoughts

Bill Waller and I went to the Ft Desoto park in St Petersburg, FL, on Mar 5, where the WaterTribe Everglades Challenge and Ultimate Florida Challenge would begin the next morning.

Jim Czarnowski (engineer in charge of Hobie AI Tandem) was busy assembling an AI Tandem. He cheerfully put up with us over the next couple hours as we took pictures of his boat and asked questions. We came away with these points (any errors are mine—Chekika)

• The AI Tandem has minimal propensity to dive. (They are working on a bow wave deflector for the AI Single.)
• Amas are 4' plus longer (13' 4” vs 9' on the AI single) and extend forward to within 1' of the bow (see picture below.)
• Beam is 30" wide (vs 27.5 on AI single) with much more volume in the bow to help prevent diving
• Sail is 18' tall
• Hull is ca. 18’ long
• Hull weighs 115 lbs; rigged weight 190 lbs (according to Hobie product site)
• 2 Sturdy carry handles on each side of hull (see picture below)
• Aka/xbar connection redesigned—sturdier & easier to connect (see pictures below)
• Dagger board retracts into hull using a lever which is integral to the hull
• Cockpits are 1" longer
• Rear, top cargo area is much smaller (just big enough to hold the Hobie Bait Well).
• Rear TnS hatch has slanted surface reducing water entry while sailing.
• Hiking pole for steering is a prototype (see picture below.)
• AI Tandem is designed for addition of a jib (see picture below)
• The jib is a prototype (but near production according to Matt Miller).



Pictures:

Amas are 3’ 4” longer and positioned much more forward than those on AI Single


Carry handle; note knob on rudder control


Aka – Xbar connection: Strong and easy to connect






Prototype hiking out steering pole


Note furled jib on Jim and Elena’s boat


In summary, I am of the same opinion as Bill Waller—the AI Tandem is a powerful upgrade of the AI Single. It seems to be a great boat, building on Hobie’s experience with the Single. And, perhaps best of all, it seems to be a great price.

That said, I don’t think I will be buying an AI Tandem soon. I have 2 AI Singles, and my wife loves to run her own boat whether it is a kayak or an AI—“lots of personal satisfaction.”

I also came away with an appreciation of the tramps which I had not had before. The tramps can carry a lot of gear for an extended expedition trip. Jim Hall is doing the UFC using an AI Tandem equipped with tramps. He is carrying sufficient food to last 30 days—the maximum length of the UFC. When I asked him what he was going to use the tramps for (before he had loaded much of his gear on the tramps), he said “I may sleep on them.” That sounded like a great idea. During his UFC journey circumnavigating Florida, there will be many times when there is no place to set up a tent—the tramps could come in very handy.

Jim Hall has already rescued 2 people from a capsized sailboat during his UFC. Piloting his AI Tandem, he actually picked them out of the water and carried them on his tramps to safety on shore. He did all this in very rough seas with an expedition-loaded AI Tandem.

Keith

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2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon

so awesome, the new crossbar connection looks really good, hopefully an AI upgrade.

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Wow, interesting idea, Dave. I asked Jim Czarnowski if one could put the AI Tandem amas on an AI Single. He thought it was possible, but was concerned that the akas/aka connection might not be strong enough for the larger amas. You have come up with the solution: Upgrade the AI Single w/ AI tandem Xbar/akas and amas. When that is done you would have a much more sea-worthy AI Single (less submarining), and, of course, you would have the new Xbar/aka connectors. Brilliant!

Keith

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2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon

On the question of the bow behavior on the TI, perhaps more data is required. The water tribe site has some video of the TIs that are in the EC 2010 event and one of them - I think a video of pelican and ocean diva -- seems to show the bow of their TI behaving in the manner of the AI. The bow appears to cut through and underneath waves as usual. It seems evident that if the new TI design reduces submarining to some extent, it doesn't appear that it eliminates it.

Now I wonder if that new steering lever can and hiking stick be swapped onto the AI. That looks like a great redesign

Since the first photos of the TI, have been hoping that the 2011 AI will have the new akas and amas in Dune, of course. The new rudder handle and bar would be great also.

If anything sell the parts as part of new adventure/AI upgrade kit.

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Timo--yes, as mentioned on another thread, there appears to be a bit of diving on the AI Tandem in that video clip. That clip shows OceanDiva sitting as far back on the stern as possible to reduce the diving. I think the deal is that when you get these boats expedition loaded, even the Tandem will dive a bit. Again, as pointed out in the contentious thread about the AI Single diving, it is the basic hull/ama design (little or no rocker) which provides higher speed but encourages cutting through waves and diving when loaded. Still, the Tandem is a better anti-diving design than the Single. Maybe, when Jim Czarnowski designs a bow wave deflector for the Single, he'll do one for the Tandem.

Keith

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2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon

I guess the heavier person should sit in the rear seat when there is big waves. I guess there will be less diving without the jib. And I guess there is no diving problem at all if you're sailing the TI on your own and steering from the rear seat. Is it possible to handle the jib from the rear seat?

I too would like more info about the furling jib to enhance speed and control CE balance.

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Marc K
2010 Hobie Tandem Island
Boynton Beach, FL

Hobie Crafts,

I think you can handle everything from the rear seat. The tramps are probably more important on the Tandem than the Single, because they allow you to easily move all about the boat, including up to the bow if you need to work on the jib. I don't know if you have seen another video of Pelican (Nick Hall in the WaterTribe Ultimate Florida Challenge) on his heavily loaded AI Tandem when he rescues 2 people who have capsized in heavy seas. As he is taking these 2 men to shore, they are shown first with their upper torso on the tramps but near the bow. I suspect there was some diving in the heavy seas. The next time you see these fellows, they have switched and their feet are up near the bow and their torsos are more midship.

Keith

_________________
2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon