Long term effects of aftermarket fins

[mraz72]

Just yesterday I took my '16 242 for the first time ever. Last year I had a 19' 2015 192 (n0 articulating keel), the difference might have been noticeable (barely), but as you said, I still had to babysit the steering wheel at slow speed.

 

[2kwik4u]

I don't have a comment on the durability of fins (so perhaps my comments are better shared elsewhere), however I don't quite understand them.

We had a standard 19ft runabout I/O boat for years. Made the move the the Yamaha AR190 with an articulating keel. It "wanders" at low speed about the same as our old I/O boat. It does require constant "babysitting", but isn't that kind of the point of being in the captains seat? Paying attention to whats going on and where you're headed? This boat does "spin" faster if you get off center, and requires slow and small inputs to stay online, however it took us all of two outings to get the hang of it.

My main comments though are aimed at the "safety" aspect of the fins. We have all bought in at some level to the "it's safer without a prop" mentality, and for a lot of us that was a deciding factor in getting the boat. Now we are immediately (sometimes before even a first drive) screwing large thin metal objects to the area directly under the swim platform. I know my boat doesn't and won't have the fins, but the articulating keel has already drawn blood from our 5yr old kicking it while playing/swimming around the back of the boat. Adding these fins is no different than having a prop back there IMO. I suspect he wouldn't have drawn blood from just kicking the pump (which he certainly would have), but instead he had a "sharp" corner to catch his foot on.......NOW.....with all that said, it was an important lesson that everyone needs to learn when being around the back of a boat. Keep away from the drive unit, whatever form it takes, to avoid injury.

Cliff Notes.....I just don't see the benefit of the fins for our boat. It tracks just fine with a little practice, and I don't want to put more sharp objects near my feet when swimming.

 

[swatski]

Adding these fins is no different than having a prop back there IMO.

What?????

No offense but that has got to be a slip of the tongue. Or - one of the most rearward comments I have seen in awhile. IMO, of course.

EDIT: Also please do not install trim tabs. Those will cut your legs off.

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[Julian]

What?????

No offense but that has got to be a slip of the tongue. Or - one of the most rearward comments I have seen in awhile. IMO, of course.

EDIT: Also please do not install trim tabs. Those will cut your legs off.

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He is referring to swimming around the stern WITHOUT the motor running....anchored. Yes it adds more metal that you could contact. I loved having fins on my SX 230 and LX210. I've not added them to my 242X as the keel and rudder give me about what I had with fins on the older model...so I'm good with that. I'm sure adding fins would give me even more control, and I might test out someone's boat at either Bimini or Shelbyville this year to see how I like it. Nothing like a side by side comparison to eliminate all the conjecture/opinion. I know someone is bringing a drone to bimini....perhaps we could even do a turning test.....???(if someone coming has fins on a 24' keel model)

 

[swatski]

He is referring to swimming around the stern WITHOUT the motor running

Sure. But you are still ONE KEY-TURN AWAY from turning that screw into a human meat grinder.



Regarding fins and turning radius, I think there are many misconceptions. Fins, like rudders, in jet boats are not for everyone.
For starters, the new Yamahas with "articulating keels" turn "tight" but with a LARGER turning radius as compared to older Yammies and all BRP boats with flat bottoms. That's because those new keeled hulls don't slip-slide sideways, almost not at all. Fins make those turns even less prone to side/slip-sliding at the stern, especially if the fins are set to stay down at speed. (Which - BTW - is the only way I'll have it)

So - the net effect of running with new keel, rudder, fins is more control but WIDER turns - if you want to compare those to slide-turns of traditional (keel-less, rudder-less, fin-less) jet boats.
I would imagine that would be very apparent in drone-footage.

In the new yamaha hulls the AK (Cobra) fins are also huge help to turn the boat at speed - especially when trying to slow down at the same time - those new hulls plow through water like tree logs.

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[2kwik4u]

Yes, I was referring to swimming around the back with the engine off. Lots of sharp metal to bonk your feet on already, why add any more? I already don't like the articulating keel back there. The fins are what 1/8" aluminum plate? Very similar thickness to a standard prop, stainless props can be thinner at the edge I suppose, but are still a giant pain if you kick one.

Sure. But you are still ONE KEY-TURN AWAY from turning that screw into a human meat grinder

As to the single key turn away from a human meat grinder......have you read the warnings about water injection from the jet pump? I think that argument is a moot point as you shouldn't be that close to the rear of ANY power boat with the motor running. Have a foot chopped off, or have a bodily orifice injected with high quantities of high pressure water.......I don't think either of us want either of those scenarios to play out, ever.

Also, I had automatic adjusting trim tabs on the last boat. I kicked one of those once too. They also hurt very much badly. As I said in my first post up there, it was an important lesson for the 5yr old to learn. Be careful around the sharp/hard objects that stick out of the back of a power boat when swimming near there. I doubt he does it again anytime soon, and it didn't hurt him bad enough to scare him out of the water for good, so it's really not a huge ordeal.

The point of my original post was that I don't see a scenario where the fins added enough benefit to justify the kick hazard and the cost. I could be completely wrong as well, lots of people buy them, like them, and have had them for years without an issue.

*edit*

Just read the post about the previous hulls having a flat bottom......Have a look at the new 19ft Yamaha's. There is a significant flat spot where the jet intake grate is. I suspect this is why it "slips" more than my old runabout.

 

[Scuba_ref]

Now we are immediately (sometimes before even a first drive) screwing large thin metal objects to the area directly under the swim platform. I know my boat doesn't and won't have the fins, but the articulating keel has already drawn blood from our 5yr old kicking it while playing/swimming around the back of the boat. Adding these fins is no different than having a prop back there IMO.

My fins are not thin metal objects and are not screwed in place. The have considerable give in them as they retract fully when at speed. I spend a lot of time travelling between 0.5 mph and 1.0 mph as I use one engine at idle speed for trolling. Without the fins it would be impossible to maintain any sort of consistent track or speed at those levels. You have quite strong opinions regarding fins for someone who has never used them.

 

[Julian]

As to the single key turn away from a human meat grinder......have you read the warnings about water injection from the jet pump? I think that argument is a moot point as you shouldn't be that close to the rear of ANY power boat with the motor running. Have a foot chopped off, or have a bodily orifice injected with high quantities of high pressure water.......I don't think either of us want either of those scenarios to play out, ever.

Sorry, just simply not a valid comparison. I'll take the impact of jet wash when someone puts it into gear vs impact with a prop when someone puts it into gear EVERY SINGLE TIME! NO COMPARISON! I get your point, but it doesn't work for me. Yes, full throttle jet wash up an orifice would be a bad thing....but that is one use case out of many alternatives.

@swatski You are correct about the turning radius etc. My point is that I only ever enjoyed fin use at lower speeds....if fins on a 240 boat with a keel don't improve slow speed tracking or turning radius, then they don't do anything for me. Measuring tracking would be hard to QA, turning radius...not so hard. If you are saying they don't help with turning radius...then that adds to my choice not to add them to my keeled/ruddered boat. But now that we have different hulls, results vary and we have to be careful not to paint all the boats the same way! Also, keels and rudders are different sizes between the 19 and 24' boats! MUCH bigger on a 24'....so fins might make a much bigger change to the 19' line up.

 

[swatski]

Have a look at the new 19ft Yamaha's.

There is no such thing as a new 19ft Yamaha hull, the same hull first introduced in 2012 MY. The new models have a "rudder" or "articulating keel" appendage fixed to the ride plate, but no hull "keel". And yes, you can still "drift" with that hull, as in car drift, unlike with the new keeled ones.

As for your other quote:

As to the single key turn away from a human meat grinder......have you read the warnings about water injection from the jet pump? I think that argument is a moot point as you shouldn't be that close to the rear of ANY power boat with the motor running.

I'm not even sure WHY I bother to respond to these comments. This belongs on thehulltruth, lol.

But I do like to take my earlier "rearward" comment about it back. And replace it with "ignorant".

All that IMO, of course, lol.

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[swatski]

If you are saying they don't help with turning radius...then that adds to my choice not to add them to my keeled/ruddered boat.

Well, yes and no. The AK Cobras help tremendously when running at speed AND slowing down. The 2015+ 24ft boats limit the reverse thrust available at speed, and it is virtually non-existent in E-series. That is a well know flaw in the new boats, it can be very DANGEROUS, and I'm afraid that if Yamaha does not correct it they may find themselves paying for it. Steering a 24ft long log without thrust at 40-50mph is an issue. Which is greatly aided by the AK Cobra fins, a very significant safety and accident-avoidance feature.

I agree with you that in the new 24ft keeled hulls the fins' influence is way more limited as compared to other models. For example, the influence of Cobra Ultimates in my 190 at no wake speeds was a lot more tangible than the influence of Cobra AKs in my 2016 240. Still, the AKs would be my first mod - for a reason.

But now that we have different hulls, results vary and we have to be careful not to paint all the boats the same way!

That is so true!


Being relatively new to jet boating, I come to places like this one to educate myself and save some effort and money of not needing to learn everything the hard way. I have been rewarded with access to unparalleled information pipeline, and able to enjoy my newly found jetboating hobby a lot more and a lot faster. As a token of appreciation, I try to share my own experience and contribute back to the community.

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[Julian]

The AK Cobras help tremendously when running at speed AND slowing down.

I'm just going to have to test them out while we are at Bimini!

 

[Cobra Jet Steering LLC]

My goodness I think more people who have actual experience would be a good reference for fins or no fins since I have made so many different styles over the past 15 years I would think the latest styles like the VIPER or the ULTINATE or MAGNUM A K systems and even the regular Magnum sets have proven themselves time and time again. Most recent comment posted about a 19 foot boat https://jetboaters.net/threads/cobra-jet-steering.13786/ for example.. and I continue to improve the systems when I see a reason to or to meet a need it is interesting that today I had a conversation with someone with a 24 foot Yamaha keel boat who is removing his rudder for safety reasons and installing a full set of ultimate steering with fangs, I can't wait to hear the results. Historically there has always been and I suspect always will be naysayers for whatever reason imaginary or real, conceived or misconceived but the truth is steering for jet boats was way overdue. I know first hand, here is how I came to invent jet steering enhancements and then obtain patents and sell them over the many years and continue to meet the needs of jet boat owners that feel like I did.


Cobra Jet Steering was actually born out of necessity. I was always involved with boating from an early age, even before I was old enough to drive a car. I loved being on a boat. I delivered newspapers, flyers anything I could do to earn enough money to purchase my first boat back when I was about 13 or 14. I made a deal with my dad that if I worked to buy the boat and trailer he would buy the motor and pay for a wetslip in a local lake. I followed through with this and was the proud owner of a 14 foot runabout with a 40 hp Evinrude.

This was in the middle 60s. I rode my bicycle several miles to the marina every summer morning to get that boat out and go water skiing. I used the boat to pay for the fuel costs by pulling my friends skiing for 50 cents each. Gas was 23 cents a gallon back then.

In 1972 at the age of 20 I decided the snow was not for me after the first snow fall of the season in Massachusetts I moved to Florida with everything I owned packed in my 1995 Plymouth Barracuda.

Now I was in boating heaven on the Gulf of Mexico. All My life I boated regularly even if all I could afford was a 12 foot boat with a kicker on it.

I raised my 4 children on the water frequenting the local islands often camping on them for 2 weeks at a time every June when school let out.

In 2001 I purchased a small jet boat from a local private owner, this boat looked really clean and I thought it would be perfect for taking my family water skiing, tubing and driving around playing in the Florida waters.

Even with all my boating experience I was totally unaware of the handling shortcomings of jet boats.

I anxiously launched my boat for the first time and within less than a minute I was totally disappointed and saddened because this boat was impossible for me to control , predict or trust after all those decades of operating a conventional boat I received a rude awakening, jet boats were not for me!

I spent the next few days deciding that I was going to sell this boat even if I lost money as it was just not going to do the job , I was convinced it was dangerous and I would not put my children in this THING!

Eventually I had an idea what if I fixed the lack of steering control , then I could enjoy the boat and so could my family.

I decided that I was either going to fix the boats steering deficit or go down trying. My first attempt was to make special adaptations to the existing steering system attaching tie rods to the jet nozzle and interconnect rudders attached to the hull spaced apart from the center of the boat to protect them from striking the ground.

Totally custom fabricating this prototype system really did not take me very long to construct and install .

I took it to the water to try it and it immediately WOWED me. I had a smile on my face and I was relieved because I went all in doing this modification even drilling holes in the transom for the mounting the bolts and cutting out and installing inspection holes in the floor to access the bolts.

In a few minutes I knew I had saved the boat and I was so impressed with the transformation that I eventually decided to expand on it and seek a US patent for improving jet boat and p w c steering.
Interestingly during the years I owned that boat I loved it and I really enjoyed it's handling characteristics. When I finally outgrew the boat I put it up for sale. I had advertised that it had enhanced steering. The very first person that came out to try it took the helm and I watched his face as he drove it, he immediately smiled as he put it through its paces.

He purchased it , on the spot, at the asking price!

That was when he told me he previously owned one just like it and how he was curious about the enhanced steering and how impressed he was with the steering system after trying it himself that he had to have it.


So I appreciate that some don't get it and some don't need it but the ones that do get it and need it are certainly relieved that it exists.

 

[mraz72]

you are adding some metal that might cause issue if you kicked it, I guess. So take your pick, improved handling or metal you might kick

BUT

The reason many of us boat jet boats in the first place was the lack of that meat grinder exposed on prop boats. I do see the wake versions of prob boats over extend the swim platform so you really can't fall into the grinder, but you could still kick it swimming near it.

Isn't the additional keel removable? I haven't looked but I thought I remember seeing a few bolts was all it took to remove, I could be wrong.

 

[swatski]

Isn't the additional keel removable? I haven't looked but I thought I remember seeing a few bolts was all it took to remove, I could be wrong.

Not in 240s. It's the hull mold. But you could remove the small rudder, or the "articulating" part of it.

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[2kwik4u]

Ok.......

"New 19ft boats" was in reference to "all" 19ft yamahas. New meaning they are new to me since I first looked at getting an AR model in 2006. So since I have only known of them for about a year they are "new" to me. My appologies for not being more clear, or perhaps not being more specific.

Back to fins......as I said earlier I don't see the point. Having test drove a local boat with and now my personal boat without add on fins the difference is negligible IMO. To say I'm ignorant of them (or in general) is pretty crappy. Lots of good will there eh?

As to the meat grinder comment. I'll let you think what you will about the preference of taking jet wash to the body over a prop. Neither will be good for you and I know both will cause serious injury. Having owned both now, I can tell you that I would rather board a standard I/O in neutral than a jet boat in neutral. With the obvious knowledge that engine off when persons are in the water is safest and the only way should do it.

I think we can all agree that we've already put our money where our mouth is and plunked down a sizable amount of cash on a jet boat, so we've already bought into the general premise of it being safer, or better, or faster, or any other superlative you care to use. I just don't get the idea of buying something that is intentionally different than "normal" and then immediately trying to change it back to "normal".

They aren't for me, but like I said before they clearly are for a LOT of owners.

 

[swatski]

Back to fins......as I said earlier I don't see the point. Having test drove a local boat with and now my personal boat without add on fins the difference is negligible IMO. To say I'm ignorant of them (or in general) is pretty crappy. Lots of good will there eh?

My "ignorant" comment was very specific - in relation to this statement (not person):

As to the single key turn away from a human meat grinder......have you read the warnings about water injection from the jet pump? I think that argument is a moot point as you shouldn't be that close to the rear of ANY power boat with the motor running.

I'm sorry, but I do not know how else to qualify a claim that a running jet nozzle is as hazardous as an outboard prop.

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[haknslash]

you are adding some metal that might cause issue if you kicked it, I guess. So take your pick, improved handling or metal you might kick

BUT

The reason many of us boat jet boats in the first place was the lack of that meat grinder exposed on prop boats. I do see the wake versions of prob boats over extend the swim platform so you really can't fall into the grinder, but you could still kick it swimming near it.

Isn't the additional keel removable? I haven't looked but I thought I remember seeing a few bolts was all it took to remove, I could be wrong.

A traditional wake boat is a V drive and the prop is not out back or under the swim platform like it is on an I/O boat. There is a big rudder behind the prop so it would be hard to kick it unless you're really tall and purposely kick down there.

 

[Cobra Jet Steering LLC]

Well here is another email I received today from a customer who is a member of this site

Thank you so much Jeff. I used your system for the first time on Memorial Day weekend, and it made an incredible difference at low speeds. It's an excellent product that made an immediate impact on the boats drivability.

I love hearing back from people that I have helped enjoy their boat and made it a more practical and safer vessel, But that is what makes me keep going. I had a phone call from a customer last night , he was impressed that he called me in the evening and I answered him personally it's what I do it's my baby and often it wears me out doing all this but I really would not know what to do if I sold it. I turned down one offer already this year, and it was my number but I just could not LET GO " YET". I just love the emails and the comments from those who enjoy their boats more now . I always try to help people when I think they need assistance even though a lot of the subjects have nothing to do with steering.
I have been on web sites a long time and unless I think you are a troll planted to cause disruptions or just a negative person trying to disrupt the site for the hell of it, I will always try to help if I can. I have always said and always believed that a person should use their boat as it was built first , then if it is not making them comfortable or doing what they need it to do they should explore the steering options that can fix the problem. I won't own a jet ski or a jet boat without added steering at all speeds it is just too much fun to do what I do on my skies. But that's just ME. But I do have a ton of hours "thousands" riding skies.

 

[DCB-270]

For us. 3 Yamaha's and no fins . we learned how to drive a jet boat a long time ago.

 

[swatski]

For us. 3 Yamaha's and no fins . we learned how to drive a jet boat a long time ago.

Sure thing. Drifting is a ton of fun, too. Just depends how you use your boat.

But - consider another common scenario - pulling a skier or wakeboarder behind a 190. Do it with or without the Ultimates.

I'm pretty sure you would keep the Ultimates. (for that)

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