This could almost go under that "gimmick" category I'm working on but, they do work!  I'm on my 3rd boat now and have had one on each of the first two and just finishing the install on my present boat.  The idea behind these "fins", according to the manufacturers is that they give you a better hole shot (getting up "on step" or plane), stabilize the boat on turns and reduce/stop porpoiseing (that bouncing up and down in the water when your motor is trimmed up to much) in the water.  Lots of other claims such as higher speeds blah blah but, after all the wrapping is thrown away I will give them this, it can make for a way better hole shot, and the quicker you are on step the less fuel you use, pretty simple!

My first boat was a 20' Four Winns with a 302 Cobra stern drive in it, you'd think it would have enough power but when loaded up with fuel and people, it actually kinda sucked outta the hole!  On that boat I put a Sting Ray fin, same idea as the one I put on my present boat, just a different style.  Big diff in the hole shot but no difference in anything else the companies brag about.  My second boat, a 24' Trophy with BIG inboard/stern drive also kinda sucked on the hole shot, even with trim tabs.  I also put a Sting Ray on it and although not as big a difference as on the Four Winns, it did work.  So, my present boat, a 19' aluminum with a 150 HP outboard on it, you wouldn't think I'd need such a fin but, its that hole shot stuff again.  Even with my boat, full load of fuel, all the extra batteries on board, fishing gear, coolers (with just ice in them of course) and toss in 4 adults, and it works to get outta the hole!  With the fin?  A little blurp on the throttle and it pops right up onto step, and at way less rpm that before!  For you guys that didn't listen to Cappy when he told you "get as bigger motor rather than smaller and are now sorry you didn't, this device just might make a difference.  Every boat is different when it comes to hull designs so this device will work better on some than others but for 50 bucks, I don't think you can go to wrong.

The installation of these things couldn't be simpler, so simple in fact, that even my buddy SCPP (Greg) could install it!  Now that's simple, no, not Greg, the install!  Take the thing outta the wrapper, read the instructions NUMEROUS times, take the fin and set it on the cavitation plate where the fin goes and just have a look at it.  Then, go back and read the instructions, again!  Its like that wood cutting rule of "measure twice and cut once".  Although it may be a little un-nerving to drill holes into the aluminum plate, by reading the INSTRUCTIONS it makes it alot easier.  With this unit there was a nifty tear out template that you put right onto the cavitation plate and it showed you exactly how to line it up and where to drill those scary holes!  Just make sure that when you have the template in the right spot that you take a bit of masking tape and tape it down onto the plate, then there's no errors when marking your holes for drilling.  Because we're dealing with aluminum here its pretty soft, so a nice sharp punch (I use an old screwdriver with the tip sharpened up) works great and also gives you a wee indent for starting your drill bit in,

I take the punch and put it right where the arrows indicate on the template and give it a bit of a rap, do all four holes of course.  You then take the template off and take your drill with a 1/8" bit or smaller and drill your pilot holes.  Now, your gonna find that the two hole closest to you are easy to drill straight up and down because the drill has lots of room.  However, those two holes towards the front are tight and your drill may not be straight up and down, that's why the smaller drill bit and if necessary, offsetting the hole just a smidge to the outside of the spot its supposed to have the hole.  What I did then for those inside holes is take the prop off, (and take it off guys, it only takes a second!) and drilled the final hole of 1/4" from the bottom up, which put the hole exactly where it was supposed to be.  With that done, the fin was all ready to be installed with the supplied hardware, make sure you put the stuff on in the right order!  Remember those INSTRUCTIONS I was talking about!

The nuts that come with the unit are a "one time" only use, so if you screw them up you'll have to get new ones.  And, they are of the Nylock nature where you don't need a lock washer with them.  I do however, still apply some LocTite to the threads of the bolt, there's no reason why I need to ever take that fin off so better safe than sorry.  The finished project actually doesn't look that bad either, especially if you get a color that matches your motor and doesn't stick out like a sore thumb!  The other thing I did do was throw a coat of wax on the plate under the fin and onto the fin itself, just a bit of UV protection and to make it even more slippery than the company claims it already is!  Oh ya, one "no no" when putting the prop back on and torqueing the nut down, do not, let me say again, do not, wedge your 2 x 4 against the fin when holding the prop in place!  I don't know if it would break it but, just don't do it, that's the easiest.  This particular fin worked better than expected on my boat, it takes very little rpm to get the boat up on step and, I can throttle down more without the boat wanting to "get off" of step.  Worth trying it out!