• Welcome to Jetboaters.net!

    We are delighted you have found your way to the best Jet Boaters Forum on the internet! Please consider Signing Up so that you can enjoy all the features and offers on the forum. We have members with boats from all the major manufacturers including Yamaha, Seadoo, Scarab and Chaparral. We don't email you SPAM, and the site is totally non-commercial. So what's to lose? IT IS FREE!

    Membership allows you to ask questions (no matter how mundane), meet up with other jet boaters, see full images (not just thumbnails), browse the member map and qualifies you for members only discounts offered by vendors who run specials for our members only! (It also gets rid of this banner!)

    free hit counter
  • Guest, we are pleased to announce that Hydrophase Ridesteady is offering an extra $100 off for JETBOATERS.NET members on any Ridesteady for Yamaha Speed Control system purchased through March 7th, 2025. Ridesteady is a speed control system (“cruise control”) that uses GPS satellites or engine RPM to keep your boat at the set speed you choose. On twin engine boats, it will also automatically synchronize your engines.

    Click Here for more information>Ride Steady group buy for JetBoaters.net members only

    You can dismiss this Notice by clicking the "X" in the upper right>>>>>

Thrust Vectors vs Cobra or ??? for 242 with articulating keel

Rod5

Jetboaters Commander
Messages
548
Reaction score
471
Points
187
Location
Marietta GA
Boat Make
Yamaha
Year
2022
Boat Model
255XD
Boat Length
25
Okay so I was pulling two tubes this weekend for the first time with the 242x and the first thing I noticed is that the drag of the tubes attached to the stern hook (not the tower) significantly affected the turning radius by tending to straighten the rear of the boat. Yes more thrust/power helped, but there was one situation where my daughters boyfriend fell off, the tube flipped and was plowing like a crank bait with tons of drag and as I try to swing around to protect the him from an on coming boat (who had not yet seen his bobbing head in the water), my boat simply would not turn around even at full power. I instantly realized what was happening so I cut all power, tub floated up, then I as able to power up and execute my turn around, but at the cost of several seconds while wife and kids are freaking out as the other boat was fast approaching and got a little too close even for my comfort. The Articulating Keel was useless in this somewhat extreme situation.
I always noticed the same exact issue when pulling skier/tubes from our wave runners, so I was very familiar with the physical dynamics going on at the time, but I was surprised it affected this big heavy 24' boat as much as it did.
So I said all that to ask this, what are the advantages/disadvantages to the different makes of fins out there? I will add that when pulling a load I want fins that will at least partly stay down in the water and not pivot up completely so that they are still affective while the boat is planed off. Price difference is not going to be a factor for me.

Thank you in advance for sharing your experiences with different solutions.
 
You realize that's like asking Republican or Democrat around here, right? :)

I added TVs but since it's my first Yamaha and no keel... can't help your inquiry much. Have to admit also never tried pulling two tubes *but* also never had any trouble cranking her around with 250+lbs on a tube.
I wonder if differential thrust (i.e. dial back - not cut) one engine to power around would have helped?
 
Ha ha I certainly don't want to stir up any political wars here... I had been trying that too, throttling back inside engine and/or maxing outside engine during whip turns both with and without pulling tubes. It has much less of an affect then you think it would, maybe 5% extra turn rate.
 
I think the cobra fins can be adjusted to not ride up at speed. TV's have no adjustment so they will ride up.
 
Neither. Not necessary to control any Yamaha.
 
Both
No but i have tried versions of both and i didn't need them and thought the boat was more fun without but my wife was greatly benefited bythem.
 
So I'm not an expert so correct me if I'm wrong Will, but the Trust Vectors lift up when going. With that said I feel up on plain the boat is more responsive with them installed.
 
I don't think any fins would have helped with the tube submerging situation. You already have a rudder and that didn't turn you. I think letting the tube float back up would be your only option.

I've had a tube submerge a couple times but I don't remember it affecting me turning that much...but I also wasn't trying to do it in a hurry just slowed down till it popped back up and then sped up.
 
I'm with others, I don't think either product would solve your tubing issue, your action of slowing down to letting the tube to stop plowing is the only way I know to solve the problem.

But if I had 2015/2016 boat and was looking to put on some fins I would have to go with the Cobra's. Don't get me wrong both are great products but the Cobra's to me have a couple of advantages; 1) the added turn buckle to balance the factory rudder load between the jets & 2) the adjustability of the fins to be either up or down at speed.
 
I have the Cobras that worked fine. I bought them mostly to help the Mrs but since she rarely drives I pulled them off but kept the second tie rod. I prefer nothing to hang below the hull. I'd buy Cobras for the second tie rod alone.
 
IMHO you did the only thing you could do to regain effective steering control.

The cobras and vectors are both are great products even if you don't need them but your crew / guest drivers do.
 
Last edited:
One thing to remember is that the new boat you own has a huge keel running the length of it, this makes the hull resist turning and want to go straight at speed so that contributes to your issues.
The other regular jet boats do not have that keel so they will be more nimble at speed and not need the same level of assistance, so it is apples and oranges.
The magnum A K series was designed as a model specific steering system to deal with the needs of that specific boat. The fangs will also be available for that system soon.
As for sinking a tube , that is quite a lot of drag and added to the keel resistance I can see why your rudder was not effective.
 
I've had that happen with my boat also. Only thing to do is let the tube float up again. That much drag you will just rip the hook out of the boat. I have the TV's, dealer installed them for free. I do like the fact that they are spring loaded so if they hit something at speed they will pop up. The spring is adjustable so you can adjust how much force is needed to push them up.
 
Thanks everyone, you all have truly shared wealth of information in less than 24 hours... and some of it was even useful! :)
I just ordered the Magnum A K Cobra fins from Jeff to beef up the keel rudder and foster some more traction on the rear end.
Thanks again everyone's sharing your suggestions!
Rod
 
Just a question....why wouldn't you attach the tube to the tower? While I have no seat time in my incoming 242X, I have countless hours pulling my kids with my AR240 and always use the Tower. The only time I ever had the tube sink was when the kids would horse around at low speed and your right about the drag. The Tower works great for tubing. Just my 2 cents
 
I was told for a couple of reasons.
1. Tub(s) tend to bounce causing load pulses, effectively hammering on the tower mounting points, more so than a skier
2. Wiping a tube out to the side, (figure eights) some have had the load of the tube pulling sideways on the boat from such a high point tilt the boat excessively. My boss told me of a scary moment with his Mastercraft in that scenario.

Again just what I've heard. My thought is our more modern boats are built much stronger in the areas that the towers mount with reenforced tower mount points...
 
Great thread with lots of topics I am eagerly eating up as I wait for my 242X.

I do not think ANY boat is going to have an easy time manuvering with a HUGE sea anchor deployed (a submerged tube is just like a giant sea anchor)....so your approach of letting it float up was right on...not to mention the huge stress you would put on the tube, rope and tow point...the weakest of those being the tube...which would tear with too much pull!

Most people on here tow tubes from their tower....although I'm not sure what percentage do this...so I'll put up a poll and lets see!

Can you put TVs on a boat with the rudder and connection points? For some reason I assume that the Cobra AKs were designed with the single outside fin because you couldn't put an inside fin on....???
 
To answer Julian about the design of the Magnum A K steering.
My steering works at all speeds not just slow speed the reason I did that was because of the large keel that will resist the boat trying to turn easily at speed, also the rack and pinion gearing that requires more turning of the wheel to get the same nozzle travel, making it less responsive, plus the single tie rod was really a bad idea in my opinion due to uneven wear and stress etc.
The rack and pinion only masks the resistance on the helm by gearing it down so you don't feel it on your end but it is still there!
However the new fangs will actually reduce it, the second tie rod balances that stress out to two sides rather than only one and the steering fins being set out so they are exposed to water when the boat is at idle or top speed but not extending below the factory rudder and keel is the best way to accommodate this setup and keep it cost effective. The system is aimed at effectiveness, balance, ease of installation, it's all there, and it even looks like it belongs on the boat. It is just common sense . So can I design a set with 2 fins per nozzle that do not interfere with the tie rods yes I can is it a good idea cost verses benefit? I don't think so. I like to keep it simple and effective. I make these to do a job and improve the boats handling at ALL speeds, not just slow speed.
 
To answer Julian about the design of the Magnum A K steering.
My steering works at all speeds not just slow speed the reason I did that was because of the large keel that will resist the boat trying to turn easily at speed, also the rack and pinion gearing that requires more turning of the wheel to get the same nozzle travel, making it less responsive, plus the single tie rod was really a bad idea in my opinion due to uneven wear and stress etc.
The rack and pinion only masks the resistance on the helm by gearing it down so you don't feel it on your end but it is still there!
However the new fangs will actually reduce it, the second tie rod balances that stress out to two sides rather than only one and the steering fins being set out so they are exposed to water when the boat is at idle or top speed but not extending below the factory rudder and keel is the best way to accommodate this setup and keep it cost effective. The system is aimed at effectiveness, balance, ease of installation, it's all there, and it even looks like it belongs on the boat. It is just common sense . So can I design a set with 2 fins per nozzle that do not interfere with the tie rods yes I can is it a good idea cost verses benefit? I don't think so. I like to keep it simple and effective. I make these to do a job and improve the boats handling at ALL speeds, not just slow speed.
I am on ur site and trying to figure out which set would be best for my boat.
I have a 2016 242 limited s e-series.
Any help appreciated.
Thanks in advance.
 
Back
Top