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PostPosted: Sat Sep 09, 2017 6:15 am 
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I have searched but without any results...
Anyone knows if there is a wave deflector on the market for the TI!

Maybe it wuld help from "submarining" going downwind in big swells?
Any thought about this?
/Gustav

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PostPosted: Sat Sep 09, 2017 7:22 am 
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Have you seen the splash guards that Kayak Bob sells? IIRC there's a discussion of hard guards (that would help in the downwind situation that you mention) vs the mesh - folks in Hawaii thought that the hard variety might create too much lift when going to weather in high winds..


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PostPosted: Sat Sep 09, 2017 8:14 am 
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The problem with "hard" splash guards is that when they do bury, and they do, it seems like the bow of your boat will never come back up.

Keith

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PostPosted: Sat Sep 09, 2017 9:27 am 
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I am thing about a wave deflector, not a splash guard.
There is a australian wave deflector for the old AI but I have never seen any for the TI?

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PostPosted: Sat Sep 09, 2017 8:01 pm 
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cool! a platypus bill...


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PostPosted: Sun Sep 10, 2017 6:52 am 
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That wave deflector has generally not been available for either the AI, AI2, or TI. My concern about such a wave deflector is that when the bow does submerge (dive), that deflector will then serve to drive the bow deeper. Note, that this comment is coming from one of the few persons who has capsized his AI2.

Keith

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PostPosted: Sun Sep 10, 2017 9:36 am 
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1+ What Keith said. I would not feel safe with it on my boat. I've taken some deep dives offshore and I doubt I would have survived well with the duck bill. Hopefully the person using it will chime in. Mingle I think?

I think you will get less submarining at the price of more pitch polling .

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PostPosted: Mon Sep 11, 2017 11:54 am 
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The "duckbill" is pointed very much upwards and its fairly small. I doubt that the surf kayakers "down under" would use them if they had a negative effect and increase the risk for submarining??
Anyway there doesnt seem to be any such product on the market specific for the TI.
:(
Well I might make a mould of the nose of the TI anyway.... one more homebrew project... :D
But this one has to brew for a long time... the wine celler is full at the moment!
:mrgreen:

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PostPosted: Mon Sep 11, 2017 1:28 pm 
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Husse0416 wrote:
The "duckbill" is pointed very much upwards and its fairly small. I doubt that the surf kayakers "down under" would use them if they had a negative effect and increase the risk for submarining??
:mrgreen:

We are NOT saying the "duckbill" increases the risk of submarining (diving). What we are saying is that if the bow dives, which it will, the "duckbill" will tend to drive the bow deeper and hinder the re-surfacing of the bow. Put another way, once the bow with the duckbill submerges, as the bow attempts to resurface, it has to lift the water on the duckbill. If there is no duckbill, the bow slices back up to the surface easily.

Keith

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PostPosted: Mon Sep 11, 2017 1:59 pm 
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Chekika wrote:
Husse0416 wrote:
The "duckbill" is pointed very much upwards and its fairly small. I doubt that the surf kayakers "down under" would use them if they had a negative effect and increase the risk for submarining??
:mrgreen:

We are NOT saying the "duckbill" increases the risk of submarining (diving). What we are saying is that if the bow dives, which it will, the "duckbill" will tend to drive the bow deeper and hinder the re-surfacing of the bow. Put another way, once the bow with the duckbill submerges, as the bow attempts to resurface, it has to lift the water on the duckbill. If there is no duckbill, the bow slices back up to the surface easily.

Keith


Of course if the kayak has lost speed when submerging the duck bill do not give lift any more. See your point..... Good thinking!
How about forming a sort of wedge ontop of the "bill" making the water flow past in a more unobstucted way up when the bow is trying to resurface? Just a thought... hydrodynamics ... not my strongest field.... :?

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PostPosted: Mon Sep 11, 2017 3:22 pm 
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The other negative effect of something larger close to the end of the bow is the wind pushing on it making it much harder to turn the bow across the wind.

While designing the early Sprayskirts we had that problem and found we had to minimize how far forward the shade-cloth was. My latest design change (2 years ago) moved it even further back with no noticeable reduction in splash deflection and no negative effects from the wind.

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PostPosted: Tue Sep 12, 2017 1:58 am 
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KayakingBob wrote:
The other negative effect of something larger close to the end of the bow is the wind pushing on it making it much harder to turn the bow across the wind.

While designing the early Sprayskirts we had that problem and found we had to minimize how far forward the shade-cloth was. My latest design change (2 years ago) moved it even further back with no noticeable reduction in splash deflection and no negative effects from the wind.


Thanks for the input Bob! :)
I usually pedal anyway when tacking upwind so I dont se a big issue when coming about into the wind (if that was what your meaning?). One of the things I love with the Island is the pedals, it sure makes tackning so much easier! :D
The size of the wave deflector is very marginal compared to the enormous wind drag from the mast anyway.
I am more concerned about the "immersion drag/resistance" from the water when the kayak tries to surface.
As usual there is only one really good way of finding out the facts concerning the pros and cons of adding a wave deflector... trial and error... in my case I learned a lot from all the errors i made!! LOL!

In the future I am planning to add a furling jib and my plan is to integrate the mount for the furler with a wave deflector.... sadly no time for that at the moment so that will be a future project.
But to design a hydrodynamicly optitimized adapted wavedeflector for the TI in carbon/resin with reinforced mountning points for the furler ... well yes I sure like the idea...
:mrgreen:

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PostPosted: Tue Sep 12, 2017 5:08 pm 
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I too, pedal when tacking. Gotta love the Hobie Mirage drive!

With the prettiest early prototype Sprayskirt at over 25 mph winds, I could NOT tack or coming about the wind, no matter how hard I pedaled. The Sprayskirt looked nice, but was so impracticable in strong wind. Also whenever it dove, it refused to surface until all forward motion stopped. I finally destroyed it.

I learned quickly to limit anything near the bow that the wind can push against. Every inch closer to the bow gives the wind more leverage.

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PostPosted: Wed Sep 13, 2017 2:28 am 
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KayakingBob wrote:
I too, pedal when tacking. Gotta love the Hobie Mirage drive!

With the prettiest early prototype Sprayskirt at over 25 mph winds, I could NOT tack or coming about the wind, no matter how hard I pedaled. The Sprayskirt looked nice, but was so impracticable in strong wind. Also whenever it dove, it refused to surface until all forward motion stopped. I finally destroyed it.

I learned quickly to limit anything near the bow that the wind can push against. Every inch closer to the bow gives the wind more leverage.


Good solid info Bob! Thanks a million!! :)
Before I put in to much effort and money in any build I will do some testing and do a makeshift version in plywood and strap it on the bow to see how much it will catch the wind. The TI surely has a long nose, over a meter in front of the mast, so I can understand that the wind really can put some leverage on the bow and stop it from comming about.
All the best!
/Gustav

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PostPosted: Wed Sep 13, 2017 5:10 am 
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How about making them out of the same cloth Bob uses on his splash guards.

Just enough to deflect most water but porous enough that water will fall through if it dives.

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