fins

[makinnat]

Im thinking about putting doel fins on my 50 hp merc. First question are they worth it. Second do you have to actually drill through part of the lower unit to install and attach to the motor.

 

[JB]

Re: fins

Hydrofoils are helpful in getting on plane at slower speed and quicker. . . if that is a problem. Doel Fins are not the most effective example.<br /><br />X dimension must be finely tuned to get best advantage and avoid increased drag.<br /><br />Yes, you have to drill the anti-ventilation plate.

 

[bigtwin]

Re: fins

I have 4 holes drilled into my anti-ventilation plate and doel fins installed. Not only can you plane at a slower speed (like JB said) it staibalizes my boat giving me a smoother ride. I also have less bow lift on acceleration, for better visibilty, however my boat dosn't have power trim. I don't think it is worth drilling into your anti-ventilation plate and the extra drag caused by the fins if your motor is equipped with power trim.<br />I also heard if I hit something hard enough with my fins I could break my antiventilation plate.

 

[Silvertip]

Re: fins

If you have a problem getting on plane or excessive bow lift, porpoising, etc., visit the Nauticus web site (you can buy Smart Tabs here on iBoats). These are the best thing since sliced bread and far more effective than engine mounted fins. Obviously a bit more money but the benefit is far greater.

 

[steelespike]

Re: fins

No question the smart tabs are a better fix.But I have had very good results with the doel fin on a 18 ft Cobia 120 merc i/o and on a Evinrude 50 on a 15 ft. Starcraft Nova runabout.These made planing much easier and reduced bounding around.These made it much easier for very short drivers(5ft) to see.For these to work as they are designed they need to be in the water at speed.And I'm sure they sap some top speed.But difficult to tell without a GPS or something.<br /> It is much easier to stay on plane at lower power.<br /> I think the likely hood of hitting something only with your fin is pretty slim.<br /> My mother constantly got her motor stuck in the mud and rocks at low water at her slip with no damage to or from the fin.The fin was on the outboard for over 10 years until we changed to a pontoon.<br /> The I/O for about 6 years until my neice destroyed the gearcase driving over a shoal at full bore while arguing with her mother about knowing where to go.<br /> As far as drilling holes I see no problem. Our pontoon performs very well with the fin removed and the pontoon set up can be touchy on some boats as far as ventilation problems.