On both sides of Last Dance's hull, a fin protrudes below. The sun just catches it in the image above. This appendage is important to the performance of the boat.
Powerboats traveling at displacement speeds tend to roll in a beam sea, creating a sensation that makes some uncomfortable. Large cruise ships have the same roll action, but they stabilize the boat with roll stabilizing fins. Last Dance is equipped with the same type of system found on large yachts and cruise ships.
The system is controlled by a gyroscope, sensing any movement side-to-side and correcting the movement by moving the two fins under the boat. The movement of the fins is powered by hydraulic fluid pressurized by a pump on the starboard engine. The system is one designed and manufactured by Naiad Marine, the major manufacturer of such systems.
Stabilized Marine, in Ft. Lauderdale, Florida, installed the Naiad system in Last Dance and has performed maintenance on the stabilizers. Their business is focused on only stabilizers and they are seen by many as THE experts. Many a DeFever has had Stabilized Marine engineer and install the Naiad systems on their boats. Check out their website below.
Stabilized Marine
Since we are under the boat, a couple of additional pictures should illustrate the design of the DeFever 40. She has a full-displacement hull which provides efficiency and a sea kindly behavior. The full keel provides inherent stability and protects the props. Boats with the props as the lowest part of the boat can often be seen in boatyards getting needed repair to bent props and shafts.
The props on Last Dance were custom designed and constructed by a company which makes propellers for recreational boats through large commercial boats, such as tugs, shrimp boats, and cruise ships. The new shafts and props were made in 2010.
