Whale tale...

[Pony]

Im just curious...Is there a general rule of thumb when considering the addition of a whale tail??<br /><br />I read in a post over in the repair forum by paul moir that said it would be a bad idea to put one on a 40hp. Are there any other boat and motor combos that dont work with them. For example my 25hp has one on a 14ft aluminum. Would performance be better without it?

 

[Barnacle_Bill]

Re: Whale tale...

We had one on a 16ft tracker with a 25 Merc and if it made any difference, we couldn't tell it. So we took it off.<br />I do have one on my 16ft bass boat with a 150 Merc and it makes a big difference. I get on plane quicker and can maintain plane at a lower speed.

 

[CATransplant]

Re: Whale tale...

A lot depends on the boat, how the outboard's A/V plate is oriented with respect to the keel, and other factors.<br /><br />Paul was talking about an older 40 hp Big Twin. Their design is a little different than most of the more modern ouboards.<br /><br />The question I'd ask is what symptom you want the whale's tail to correct? The easiest way to find out what it's doing on your boat is to remove it, then try the boat out. If the boat worked better with it on, then put it back on. If you can't tell any difference, then I'd leave it off.<br /><br />If you're asking about a boat/motor combination that doesn't have one, then I'd ask what it's doing that you'd like to correct.

 

[Pony]

Re: Whale tale...

Cat-<br />Yeah i just went back and re-read that other post. completely missed the part about the lower cavitation plate. my bad....<br /><br />I want to take mine off to test it, but i have a few issues.<br />1) waiting to put a new prop on<br />2)I have no tach or gps, and my locator wont register mph past a certain point. So I really couldnt gauge anything.<br /><br />I guess I add this question. What sort of differences should I be looking for? If there isnt a noticeable difference should i leave it on because of the holes it will leave here its bolted on?

 

[JB]

Re: Whale tale...

A hydrofoil is a partial solution to a problem.<br /><br />If you have the right problem it will help. If not, it may hinder.

 

[umblecumbuz]

Re: Whale tale...

Pony,<br /><br />The holes are not an issue, except cosmetic.<br /><br />If you want, you can fill them with normal auto body filler (ignore screams of protest from other posters!) and spray over with a matching aerosol.<br /><br />So don't base a boat running decision on a few small underwater holes in your AV plate.

 

[Pony]

Re: Whale tale...

Thanks guys...<br />Once I get my new prop on later this week i will take the hydrofoil off and see how it rides. good to know the holes are only cosmetic..thanks stillfishing

 

[Pony]

Re: Whale tale...

Well today i borrowed my neighbor who just bought a gps unit for an hour or so, and we went to the lake to test stuff out.<br /><br />It was pretty windy (about 15mph) and it was the afternoon so there was a pretty good chop out there. it was white-capping a little. <br /><br />With the wind at my back the numbers were<br />29.1mph with whale tail<br />28.0mph without whale tail<br /><br />I also noticed that the bow stayed down much better with it on, but it seemed slightly harder to turn...not sure if that makes sense.<br /><br />Given these results i guess it seems right to keep it on...my question now is what causes the increase in top end speed?? and does this seem like about the right speeed for this set-up (14ft alumacraft, 25hp johnson, 2 people weighing 330 or so combined)???

 

[CATransplant]

Re: Whale tale...

Sounds like six of one and half-dozen of the other. YOu gain an insignificant amount of speed, but the boat rides a little flatter on the water. It's also a little harder to turn.<br /><br />Really, I can't see any reason to remove the thing. The flatter ride is nice. You're at about the right speed for that boat and motor combo, I think.<br /><br />Keep it or remove it...it comes out just about the same, it seems to me.

 

[Pony]

Re: Whale tale...

Thanks for the response CAT-<br /><br />Yeah I think I will leave it on, I do enjoy the smoother flatter ride it gave. Plus then I dont have to worry about the holes in my av plate. I know that stillfishing said they were cosmetic, and I could easily fill and paint...it would still bug me. I can't even use bungee cords with my boat cover that are different colors than each other, and besides that they have to be the same color as the cover itself.....how could i ever live with those holes. LOL.