What Is a Whale Tail?
A whale tail is a 0.190-inch-thick piece of aluminum that bolts directly onto the intake of an outboard jet pump. It acts as a hydrofoil, creating stern lift and helping the boat get on plane more quickly.
It can also help reduce porpoising, which is when the bow bounces up and down because the boat is not properly balanced. Sometimes that imbalance is necessary for shallow-water performance. Another benefit is the ability to keep the boat on plane at lower speeds.
Installing a Whale Tail
Installing a whale tail is very simple and can be accomplished with a single 1/2-inch wrench. Remove the three 1/2-inch Nyloc nuts from the rear of the outboard jet pump intake, slide the whale tail up over the studs, and reinstall the nuts.
The plate reduces the available thread engagement slightly, so make sure the locking portion of each nut is fully engaged. Follow the manufacturer’s tightening instructions for your pump and hardware.
If you have an older-style pump with bolts that hold the intake to the pump, this is a good time to contact Specialty Manufacturing in California and order an intake stud kit. The bolts can be replaced with stainless-steel studs and nylon-insert locking nuts, which are used on newer-style intakes.
That’s it! Once you have the tail bolted on, you are ready to hit the water.
How Does a Whale Tail Work?
A whale tail acts as a hydrofoil, creating lift at the rear of the boat and helping to pop the boat up out of the water. The idea is similar to holding your hand out the window of a moving car. When you tilt the front of your hand upward, the air pushes your hand up. A whale tail works in a similar way by forcing water down and helping lift the stern.
Should You Get a Whale Tail for Your Outboard Jet?
If you’re having trouble with porpoising, you should seriously consider adding a whale tail to your outboard jet. If quicker acceleration is your only goal, a four-blade stainless-steel impeller may be the better first upgrade. If you’ve already upgraded the impeller, a whale tail can be a useful and relatively inexpensive addition that helps decrease the time to plane and keeps the boat on plane at lower speeds.