Hobie 16

General Sailing Discussion
Bill Roberts
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Location: Stuart, Florida

Hobie 16

Post by Bill Roberts »

Question of the Day: How long is a Hobie 16??? Does anybody know???
Bill
Mac M
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Boat Make/Model: SC17
Location: Lugoff, SC

Re: Hobie 16

Post by Mac M »

Ill bite. 16' 7"
gahamby
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Re: Hobie 16

Post by gahamby »

Are we looking for LOA or LWL?
Bill Roberts
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Re: Hobie 16

Post by Bill Roberts »

What is the maximum length of a H16? This includes the deck.
gahamby
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Re: Hobie 16

Post by gahamby »

http://www.hobiecat.com/sail/hobie-16/

I don't have one in my yard to measure. What's the point?
Bill Roberts
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Re: Hobie 16 Influence

Post by Bill Roberts »

The length of the H16 played a major role in selection of the length of the SC17 at 17 feet. The first requirement for the SC17 was that it had to be faster than the H16. Steve Edmonds and I felt like we had our necks stuck way out when selected the final design for the SC17. A hull like the 17 had never been tried before as far as we knew. The 17 was the first "shared lift" boat that we designed. The front 4ft or 5ft of the 17 is a deep V hull shape. This part of the hull is designed to split waves and generate lift, side force against the sail's side force. The bow generated side force is only half of the total side force required. The other 50% of the side force comes from an oversize rudder. You could call this rudder a steering centerboard. The resultant center of effort of these two side forces is located half way between the main beam and shroud chainplate, right where it should be.
Making the hull generate all of the side force is a high drag way to generate side force. Hulls have a lousey aspect ratio underwater, much less than 1.0, so the induced drag and the hull slippage angle are very large. The 17 design requires the hull to generate only half the side force and a high aspect ratio rudder/centerboard generates the other half. The total hull drag of a 17 is significantly less than any other boardless beach cats. This is the primary reason the SC17 is faster than other boardless beach cats and has a lower PN. Put a spinnaker and a rock star sailor on a 17 and you have a boat with a PN in the high 60s.
The 17 hull shape has another advantage. The deep V forward hull sections transition into an ellipse cross sectional shape, round bottom, as the hull approaches the transom. The aft few feet of the 17 hull are elliptical underwater, no hard keel corner all the way to the transom like all other beach cats. This round hull shape just forward of the rudder lets the rear end of the boat slide sideways in response to rudder commands. A nonsymetrical hull shape carries the hard keel corner the full length of the hull, then the rudder and the aft end of the hull oppose each other with steering commands. This makes steering sluggish and tacking almost impossible requiring backing of the jib, reversing of the helm as the boat backs up etc.
I have often thought the 17 hull shape concept might be a big advantage in these around the world races. The boat would be lighter weight and simplier to build and simplier to sail/operate and faster off the wind. Then it would suffer to windward relative to a CB boat. If the windward part of the race is less than 50% of the total race time, then the boardless boat would come out on top. AS I understand the race, the boats sail to windward only about 25% of the race. Food for thought.
Bill
DanBerger
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Boat Make/Model: SC 15 w/ spin!, SC 19
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Re: Hobie 16

Post by DanBerger »

So...Bill,

What was the inspiration behind the 15? I'm smoking about every Hobie 16 out there--the 17 just hurts their feelings more!

I laid my 15 main sail on top of a Hobie 16 main and they are pretty much the same size. The roach is a lot larger higher up on my sail.

I've also had my 15 next to a Nacra 450 and a Prindle 15 (fully rigged boats, not talking sails this time). The 450 looks tiny next to mine and the Prindle 15 looks like a toy.
Bill Roberts
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Joined: November 17th, 2003, 9:13 pm
Location: Stuart, Florida

Re: Hobie 16

Post by Bill Roberts »

Hi Pro,
I'm glad you asked. The 15 is both a 1 and a 2 person boat. Therefore it must carry almost exactly the same weight as the SC17. Therefore the SC 15 was built from the SC17 plug. Two feet was cut off from the transom of the 17 and the beam saddles were moved forward. That is all that changed. The underwater hull shape is the same. Therefore the design philosophy is the same. I'm not surprised that the SC15 is as fast or faster than the H16. The shared lift concept works very very well in a boardless beach cat idea.
Bill

PS Put a 17 rig on a 15 and they might run the same. I wouldn't be surprised.
gahamby
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Boat Make/Model: SuperCat 15#315
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Re: Hobie 16

Post by gahamby »

How much more sail area on a 17 compared to a 15?
Bill Roberts
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Re: Hobie 16

Post by Bill Roberts »

I don't remember the sail areas today. It has been too long ago. Check with Tom H. or go to the factrory web site, Aquarius-Sail.com .
I do remember that the 15 had a small sail plan on it because it was a boat for the "beginner sailor". The 15 can handle a 17 sail plan because the hulls are identical except for the last two feet at the transom. The boats have the same max righting moment because they are the same width and they have the same pitchpole resistance because they have the same front end hull shapes.
Bill
SC15Av8or
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Re: Hobie 16

Post by SC15Av8or »

Well dag nabit Bill !!! Why did you have to go and put that idea in my head. I just saw a posting for a SC17 parts boat too!! I know what I will be doing with the next one I find. Look out Dan !!!
Lifes 2 short for cheap GROG
SuperCat 15/19Av8or
havliii
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Boat Make/Model: SuperCat 19, Modded SC20
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Re: Hobie 16

Post by havliii »

Supercat 15 - 160 sq ft
Supercat 17 - 234 sq ft

reference is sailboatdata.com
havliii
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Re: Hobie 16

Post by havliii »

jus' guess'n here but I think if you add 74 sq feet of sail area to a SC15 (and we know the beams are moved forward of the 17 position) you're gonna end up with one pitchpole happy boat, no matter what the buoyancy of the bows happens to be.
Bill Roberts
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Re: Hobie 16 Influence On SC17

Post by Bill Roberts »

Hey Hot Shot,
The front beam on a 15 is 1ft further forward than the front beam on a 17 as I remember. The rear beam is 2ft forward relative to a 17.
The only contribution toward pitchpole that the mast/rig plays, is its weight is 1ft further forward on the 15. Tell old Pro to sit 6 ins further aft on his 15 and all is equal as far as mast/rig weight goes.
Bill
DanBerger
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Boat Make/Model: SC 15 w/ spin!, SC 19
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Re: Hobie 16

Post by DanBerger »

You know, everyone talks about putting a larger rig on boats and it usually never ends up well. I know there are tall rig Supercats (TR20, 19XL) but I really just don't see it as a benefit on the 15!

I know Bill can justify it, I'm just on a different page.

I think that a 17 with a 15 rig on it would be a pretty fun boat--a few more feet of waterline and manageable sail area.

and...Robert: Bring it. :twisted:
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