# Whale tails



## FredHook (Sep 6, 2014)

So what are the thoughts on a whale tail ? I have one on my boat and I just want the best performance possible. I have a Alweld 17/52 with a 98 yamaha 60 horse jet. I've heard if your rig is set up correctly you don't need one. But on the the 2 jets I've owned, they've been on both of them.


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## dhoganjr (Sep 6, 2014)

When I first got my boat with the 115/80 on there,if the water had any waves it would start to porpoise anytime it was trimmed up on plane. The whale tail eliminated it, and I have always ran one since. With it on there I can run across the lake on plane even with heavy boat traffic, heavy chop and waves. I just bump the trim down a bit to drag the whale tail in the water causing the bow to plow just a little to break through the waves, I can generally maintain about 30-35 through all but the biggest of waves.

They do cut a little off of the top end, especially with smaller hp motors, because they don't get enough speed to lift out of the water and have a little drag.

I have never ran with and without to test except for the 115 that I couldn't run on plane without, so it didn't matter anyway. 

If you really want to find out take the whale tail off and see what it does without and then you will know for sure. If the bolts are not short enough, get some new ones to test with. If you decide to test it report back and let us know your findings.


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## richg99 (Sep 6, 2014)

I don't know about jet boats, but...if you want a nice comparison between the effects of a whale tail and the use of tabs...go to the Smart Tabs site. They have a pretty convincing discussion on the two.


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## onthewater102 (Sep 6, 2014)

Not really - they attempt to make an argument against hydrofoils on V-hulls based on an idea that the hull is somehow unstable side-to-side relative to the the central low point on the V - as if the V were sitting on dry land and you were trying to support it from the center of the boat via the motor. This is completely wrong - both sides of a V hull are supported by contact with the water - but as it's a marketing video, so they wouldn't ever include an educated opinion calling them out on this fairly egregious error. They make no mention of flat-bottomed boats (alla our tinnies) who even with mod-v hulls are all planing boats designed to plow as little water as possible.

I've got hydrofoils on both my 18' fiberglass and 14' jon, but I've always had it on the jon so I only noticed differences with the fiberglass boat - but it definitely got on plane faster (at a much lower speed) with they hydrofoil than without it. The 18' did lose a little top speed with the foil, but the loss was far outside the legal speed limits on all the lakes around here so it didn't matter.

Not sure how they would hookup on a jet boat - a pic would be interesting. The foil is going to function the same creating lift no matter what type of propulsion drive you have (Bernoulli's principle), so it will also add a bit of drag. I'm wondering if they're mounted inverted on a jet boat to keep the propulsion system in the water despite the boat's attempts to plane.


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## richg99 (Sep 6, 2014)

Having owned both..one tail, and 3 Smart tabs (2 installed on flat bottomed carolina skiffs) ...the tabs (any tab system) is well worth the money.


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## FredHook (Sep 6, 2014)

I do have small tabs welded on to each corner on the transom. They are maybe each 1 1/ 2x 6 " tabs plus the tail.


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