Stabilizers & Planing Fins

[S1M2L3J4]

I own a 12'9" fibreglass boat which is fitted with a 55HP Yamaha weighing 90 kilos. Boat is driven from the stern seat by means of a central console. The boat has a seat amidships wherein the battery is located, a bow seat wherein the standard 25litre fuel tank is located and a forward anchor locker containing an anchor and a quantity of marble granules for ballast.<br /><br />The boat had a raised bow and was initially porpoising and cavitating significantly which situation improved considerably with the marble granules up front and the manual tilt set to the furthest inward position. However it still does not get out of the hole completely or in simpler words it does not plane smoothly on the cavitation plate.<br /><br />Prior to putting in the marble granules as front ballast I steered the boat from the seat amidships and the boat planed perfectly with no effort required to get on the plane.<br /><br />I would like to get rid of the marble granules since when a reasonably sized person sits on the bow seat and the boat is driven slowly it takes in water even in calm seas.<br /><br />As a substitute and to ameliorate this state of affairs I am thinking of fitting either a Doel Fin or a Whale tail / peramtrim stabilizers or smart trim tabs.<br /><br />I weigh as much as the outboard - 90 kilos !<br /><br />I would be very grateful for advice on which is the most suitable and effective option / course of action.<br /><br />Thanks

 

[steelespike]

Re: Stabilizers & Planing Fins

While I have had excellent luck with the Doel fin<br /> I would now go right to the smart tabs.Run a search here. Any that have tried them rave.They even improve reverse.

 

[stratus5]

Re: Stabilizers & Planing Fins

I have a short boat with a big motor also. I found it ran best with weight in the bow, but I too wanted to get rid of it.<br />After much trial & error, in various seas & loads, I found, after much reluctance, that the whale tail worked best, and removed the smart tabs. <br />The smart tabs apply a continous pressure. On MY boat, they lowered top speed, they needed to be down pretty far to get on plane, and they added a weird pitching moment when jumping out of the water. They also dig into the bottom when you beach. <br />I was reluctant to try the tail, as it really slowed me down when I had 40hp, but with the 75, it works great. Getting on plane is a non event. Almost no bow rise. It does not hop anymore, nor does it ventilate in turns. It has more leverage back there than the tabs, and runs level at speed.<br />No more worrying about breaking the tabs off in the shallow. <br />Im not selling them, and Im not an expert, but I did find it to be the best answer for a short, tail heavy boat. I got the big hydrofoil from west marine for fifty bucks. Wanna buy some used tabs?<br />Good luck, <br />-Dan

 

[whiteman]

Re: Stabilizers & Planing Fins

My boat is a 5.5m Aluminium Cuddy with a 115 Yammie on the tail. New, it was hard to see over the dash and I had some cavitation (aeration?) problems. After about 50 hours I put on a Permatrim http://www.permatrimmarine.com/ for $A130. The improvement was immediate. I could see over the dash. Turns at speed were much smoother. As an added bonus I plane at slower speeds. And I had another step to get on and off the boat when snorkelling! I don't have any negatives although I've heard complaints about steering problems in following seas - never experienced this and I do 95% of my boating offshore. There doesn't appear to be any change to top speed.<br /><br />Highly recommended option for 1% of the price of the motor.

 

[Jdeagro]

Re: Stabilizers & Planing Fins

Stratus 5;<br /><br />I am truly sorry that you did not have the expected results with our product, however from what you mentioned I can tell you that you had to much lift from the tabs. They needed to be adjusted to less pressure and if that did not cure the bow down problem then we would have exchanged the actuators for lees resistance. I am disapointed and would only say that I wish we would have had the chance to talk. (800-233-0194)

 

[stratus5]

Re: Stabilizers & Planing Fins

Originally posted by nautiJohn:<br />[QB] Stratus 5;<br /><br />I am truly sorry that you did not have the expected results with our product, however <SNIP><br /><br />Not a problem. They came with the boat when I bought it. <br />The tabs had to be set low for the boat to plane, and I still had to lean forward. I understand how the tabs function, and how to set them up properly, and I tried many configurations, including lowering the resistance by drilling an additional hole, and moving the brackets aft on the tabs. <br />The real problem is that my setup is fairly unique, as the boat was not made for the engine weight I have on it, plus it's a very short boat. Im sure the tabs would work well on a "normal" boat, but I apparently needed the extra leverage I get by going to the back of the AV plate with the tail. I hate the thing, but in my case, it works.<br />It was never my intention to imply that the smart tabs do not work, or that I was unhappy with them. They are a quality, well thought out product, and I could feel the effect on ride & bow rise immidiatly. I could reach back & push down on one of them with my hand, (while someone else drove)and watch the effects on trim. <br />They just were not the perfect solution for my franken-boat. It's under 9' with a 220lb motor.<br />I will be using 1 tab, on the left, with a slight downward angle on it, with a rigid strut. This will trim out the massive torque which rolls the boat left at full speed,(rigid strut) and have little effect at low speed (slight angle). Opposite of your intended design. <br />-Dan

 

[S1M2L3J4]

Re: Stabilizers & Planing Fins

I am still undecided whether to go for smart tabs or a permatrim whale tail. During my many trials I drove the boat from the middle seat with successful results. I am therefore considering moving the steering console forward and the middle seat slightly backward so that I can sit amidships whilst driving. I am considering doing this in conjunction with fitting a whale tail or smart tabs. Does anyone think that this dual course of action would resolve my problems ? Would the smart tabs or the whale tail be the more effective on this 12'9" boat with 90 kilos of outboard and 90 kilos of human at the stern ?

 

[Silvertip]

Re: Stabilizers & Planing Fins

I've used both and Smart-Tabs are a far superior solution to the problems you are experiencing. Visit Nauticus.com and view the description.

 

[Silvertip]

Re: Stabilizers & Planing Fins

I've used both and Smart-Tabs are a far superior solution to the problems you are experiencing. Visit Nauticus.com and view the description.