Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Todd RT

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I've got a 10' Bombard (Zodiac) Typhoon 305 with the wood floor and inflatable keel.

Just curious if there is any reason to install trim tabs or hydrofoil fins on this thing. She planes up just fine with my 8hp Nissan. Does 23mph in flat water with just me in it.
 

Drowned Rat

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

On a boat that small, if I would do anything, it would be a hydrofoil. You'll probably only see any benefit from it if you put alot of weight in the back of the boat. As long as it's doing okay, I'd leave it alone. Trim tabs would be overkill on a boat that size and may even produce too much lift. I have Smart Tabs on my 14' inflatable and they are adjusted to the lowest setting. This is a very heavy boat and the tabs are almost too much.
 

Todd RT

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Cool, I used to have some of the lifters on my other boat, but they kept breaking.

Is the Stingray Jr. the best hydrofoil for this boat and motor?

http://www.marine-dynamics.com/sjr.html

BTW, what is cavitation???
 

Drowned Rat

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

The stingray is a popular one to use. Personally I think they're all generally the same.

Cavitation is when the prop "slips" in the water, ususally due to applying too much power especially in a turn.

It's different from Aeration which occurs when a vortex of air is pulled down into the prop from the surface. This is the problem that hydofoils claim to fix. Aeration can be a problem on inflatables because of their shallower than normal draft.
 

Todd RT

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Aeration is all I've had happen.

Plus the foils claim to make the inflatable steer better... Hmmmm...
 

Jgweb2000

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Feb 15, 2008
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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

We have a 6hp suzuki on our 10' zodiac, and we are planning on putting a hydrofoil like you have there on the motor, will help the boat get on a plane faster
 

Todd RT

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

I dont' have a problem getting on a plane, even with 2 of us in the boat.

I'm still not sure if it's worth buying this foil and installing.
 

Drowned Rat

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Just follow the rule, If it ain't broke, don't fix it.
 
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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Great advice Rat...Though admittedly, I'm not one to follow that.
 

mrdude

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

i had smart tabs on my 14ft bayliner and theres no comparison to hydrofoils in my opinion.. have 3 sets of foils in my basement i had tryed out and the tabs will get the boat on plane 5 times faster then a foil.. the boat will handle better as well..
but i agree with the other guys.. tabs would be overkill for such a small , light, boat with a small motor. 23mph.. and getting up fast... i wouldnt change a thing.
 

Todd RT

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Thanks Everyone!!
 

wkearney99

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Hey, can I pick up this thread with a follow-up? I've got the same sort of setup, a 10' Bombard with the wood floor panels (which are a pain in the *** to setup but that's not the issue). I've got a 6hp Johnson 2-stroke on it. It's got just enough power to get it up on plane if there's just me in the boat.

But it's pretty darn squirrely once it comes over onto plane. The slightest twitch of the tiller and it seems like it'll pitch over. There's a fine line between fun and butt clenching terror, this falls just barely over that line.

So my question is would tabs or a foil help make it a bit more stable when on plane? I'm guessing tabs would do more than would a foil as they're on the boat not the engine, right? It's not like I 'need' to run it on plane, it'd just be nice to do it with a little more stability.
 

cstellwagen

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Aug 14, 2009
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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Tabs would work better for your case but it doesn't sound like that is your issue. A 6 horse should not be making the boat perform in an unsafe manner, you may want to check the pressure in the tubes.
 

wkearney99

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

I picked up a set of trim tabs from West Marine, the fold-up kind. Made a world of difference for getting it smoothly up on plane. In calm water, that is. Before it would dig the stern in pretty deep and plow with the bow up. Usually for 10 seconds or so. Now it doesn't dig in and pops up onto plane in about 6 seconds. Can't say whether it's more stable than before as my first use was in much calmer (nearly glass smooth) waters. It was a whole lot more stable and it just FLIES along.

I'll report back with how it handles in a bit more chop.
 

Welcraft3200

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

How about smart tabs on a 10foot 3inch Caribe RIB with a 20 hp 2 stoke mercury?
 

Jdeagro

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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Let me tell you guys a true story about how and why Smart Tabs were invented.

Back in 1997 I lived in Southern CA and spent many week ends going over to Catalina Island on my 28' Carver to relax and fish. One evening my wife and I decided it would be nice to go on shore for a nice dinner. We showered and dressed for the evening, grabbed the 4 LB pet dog, hopped in the 10 ft dinghy (w 9.9 HP) and headed off to Avalon. That evening the water was unusually flat, so instead of mushing along at 3 MPH with the bow pointing to the heavens, I put the boat on plane (about 15 MPH). As we rounded the Casino point, there it was! A 35 ft shore taxi with 20 passengers throwing a nice 3 ft wake.

Yep, no choice, head into the wake. Oh I forgot, Daisy the 4 LB pet dog always insisted on sitting on the bow like a hood ornament, a critical point to this story. You got the idea! We hit the wake at 15 MPH, and the dog launches up in the air as if it were on a trampoline (a 305 Zodiac). At the same time my wife and I get drenched by the wave, which did nothing for my credibility as a captain of this vessel, nor her disposition for the rest of the evening, actually the rest of the week. Women remember the bad things forever!

Yes, I reached up in the air just in time to grab daisy's leash and pull her into the boat, actually smack her on the floor. This did wonders for our marital relationship since Daisy was higher on the totem poll than me. Not a good evening!

If this isn't enough motivation to find a way to make this dinghy plain at 6 to 7 MPH I don't no what is. I tried a hydrofoil with minimal success for more than one reason. Then I got this ridiculous idea that the boat needed trim tabs like the Carver.

A few weeks later, after banging out trim plates made in my garage from stainless steel kick panels purchased at Home Depot, and coming up with a goofy idea that Nitrogen Gas Springs just might be the answer, we were off to Catalina again. By now my wife and I were speaking again, and I had high hopes that these awful looking trim tabs would work. Just for the record, I did not ask my wife to go with me on the maiden voyage with these very first Smart Tabs. I may be crazy but I am not stupid.

To my surprise and amazement, they worked! My neighbors who saw these things on my dingy laughed hysterically, and were even more convinced that I had lost it. However, one after another they just had to take a ride, and each one wanted me to build them a set. I was not in the marine business, and had solved my problem so they could solve theirs, besides they laughed at me.

Two years later the patent was issued and I started to look for those neighbors who wanted trim tabs for their dinghy's. The rest is another story. By the way I still have the original boat and trim tabs. Some people just save everything.

True Story!

Go to this page and watch the video to see me in the dinghy. I will be easy to spot as I am the only (fat) guy in the boat.

http://www.nauticusinc.com/smart_tabs.htm
 

Shootit

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Aug 17, 2010
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Re: Trim Tabs vs hydrofoil fins on 10' inflatable with 8hp Nissan?

Thought you guys might be interested in the foil i use down here in New Zealand.
Called Permatrims well made and seem to do a great job on the Inflatables divers often use them as a step to get back onboard!
They come in Black,White,Silver and grey so can match to your motor.
 

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Swissmorgy

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Smart Tabs ST780-20 on 10' Zodiac with 8hp Yamaha (Pimp my Smart Tabs!)

Smart Tabs ST780-20 on 10' Zodiac with 8hp Yamaha (Pimp my Smart Tabs!)

Hi everyone

I have an old Zodiac S131 inflatable (10', wooden floor, inflatable keel) and a 8ph Yamaha from 2012. It goes on plane easily but rises the bow very much on slow speeds. To prevent this, I bought Smart Tabs ST780-20 (Nauticus Inc.) and installed them. As my inflatable has launching wheels, I had to install the tabs quite close to the motor.

The tabs work perfectly at slow speed! However, the water pressure on plane is not strong enough to fold them up. On plane they were still down and worked like a brake. In addition, they caused a terrible lot of water spray. It was impossible to adjust the tab setting so they fold up. I even drilled new holes closer to the hinges to reduce their pressure. I think their setting is just too strong for such a small inflatable with 8hp.

Nevertheless, I found a good and easy solution that might help other users:

tab_adjust.jpg
On each tab, I installed a lever, a rope and a clamp to fix the rope. Now I can lift the tabs manaully. (By pulling the red rope and fixing it in the clamp. I can lift them fully or partially to find the correct position.) On plane, they no longer brake and no longer spray water. At slow speed, I can let them down to do their job.

Swissmorgy
 

likalar

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Re: Smart Tabs ST780-20 on 10' Zodiac with 8hp Yamaha (Pimp my Smart Tabs!)

Re: Smart Tabs ST780-20 on 10' Zodiac with 8hp Yamaha (Pimp my Smart Tabs!)

Nice work on the solution, but there has to be a better way. Maybe I'm wrong but it would seem to be a fussy operation to reach over the engine to adjust the rope on the port side tab? Does the actuator on the tabs allow for any adjustment? I've heard good things about these tabs. Did you notify the manufacturer of the problem? Maybe they have some good advice or replacements for what may be a faulty part.

Larry
P.S. You posted your question on a really old thread. You may get better response by making a new thread. Good luck.
 

Swissmorgy

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Re: Smart Tabs ST780-20 on 10' Zodiac with 8hp Yamaha (Pimp my Smart Tabs!)

Re: Smart Tabs ST780-20 on 10' Zodiac with 8hp Yamaha (Pimp my Smart Tabs!)

Hi Larry,

For sure this is not the very best option. However, according to my experiences, Smart Tabs cannot be adjusted properly on very short and light inflatables like mine because the actuator (the softest there is) is simply too strong. Even on the "softest" adjustment position they don't fold up on plane. (Neither did they on the extra position I setup myself) So my only option was to uninstall them again (and store in the basement) or to make up something that makes them usable. In my small inflatable, I can easily reach the ropes on both sides. And again: at slow and half speed they do a perfect job!

I contacted NauticusInc and they answered immediately. But they only referred to the point of the water spray, which indeed is (partly) due to my tabs close to the motor. Nauticus didn't answer the point that the tabs brake the boat because they don't fold up on plane.

I posted here because the thread well placed here for Google. In addition, nauticusinc.com refers to this message board as well. I just thought this might be useful for someone someday in a similar situation google-ing about it.

Swissmorgy
 
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