Davis Instruments 448 Whale Tail Wind Vane - 1 Pack for Accurate Wind Direction Measurement - Perfect for Sailing, Weather Monitoring, and Outdoor Activities

I put this on my pontoon because I heard it can help with prop ventilation. I tried different props but this by far made the biggest difference. Eliminated 90% of my problems. I did modify it a little and painted it Yamaha grey.Too large for my motor!Works well and installs easily...provided you use your own high strength stainless hardware. The hardware that came with the unit was brittle and two of the four bolts snapped off while being tightened. And it occurred prior to the nut being seated so the force on the bolt was not over torqued...but snapped off anyway during tightening. A quick trip to Ace Hardware for good quality stainless hardware and it was easy after that. On the lake I did notice that my speed was up by a couple MPH at full throttle and trimming up resulted in almost no rooster tail.Strong and easy to install.Works Great, Materials are excellant.It has made a big difference in me getting the boat to plane. ThanksTom AltonEasy to install & does everything it claims. I guess my only question is why motor manufacturers don't add this on their own? In any case, I would highly recommend this addition to anyone!Davis Whale tail mounted on my Crestliner 1800 Fishhawk with a 125hp Mercury Outboard.Mounting was straightforward. Just line it up, drill the holes and bolt it on.I noticed a difference in getting on plane right away. The boat is a welded aluminum V-hull that is fairly fat and deep for an 18' boat. You definitely notice it jumps right up on plane much quicker after installation.I also notice that the trim adjustment while running at speed is more responsive, and the trim seems more "true" (if that makes sense). Now, when you put the nose up, it goes up and you can either get above choppy water or lower down just enough to bash through those bigger waves. Before, there was not as much range in the adjustment of the trim - you either seemed way up or down to plow.So, a more responsive trim adjustment I would say. probably more noticeable the smaller the boat.As a side note: We have a dog and swim from the boat and the aluminum is very visible so you can tell where the prop is, and the large whale tail serves as a bit of protector for the dog (and/or small children) from hitting feet or paws on the prop. Certainly not why I bought it, but an unintended advantage.Supplied bolts were a bit small so I bought slightly larger ones that actually fit the pre drilled holes better.