Performance Data

On the return trip from the paint facility and in the open Gulf of Mexico, Force IX 81.5 Hull #1 ran approximately 30 knots at a relaxed engine speed of 1950rpm. The fuel burn was just over 130 gallons per hour and the DDEC display noted 80% engine load. The vessel was carrying over 1,800 gallons of diesel at the time of record.

The increase in performance was due to the vessel having the final layer of bottom paint applied and the stock Michigan propellers tuned.

We have boldly been predicting the projected performance of the Force IX 81.5 since the hull design was tank tested at Stevens Institute of Technology over eighteen months ago. Now, having just concluded an exhaustive series of sea trials of the fully founded hull #1, we are proud to release the performance data on the Force 81.5 Command Bridge Model

• The idle speed is 7 knots with a fuel burn of 3-4 gallons per hour.
• The 10-knot “long range cruise” speed gives a conservative range of 2,600 nautical miles.
• The 20-knot “easy cruise” speed gives a range of 1,100 nautical miles.
• The 28-knot “comfort cruise” speed gives a range of 850 nautical miles.
• The 31-knot “fast cruise” speed gives a range of 750 nautical miles.

The top speed was 34.4 knots with 92% power indicated on the engine display. The trials were conducted in various sea states with approximately 1,700 gallons fuel and ten people on board. We reserved the remaining power left in the engines to tune the propellers to the client’s particular mode of operation.

These figures exceeded our projections and the tank test data with the fuel consumption-range data well above expectations. Based on this empirical data and the tank test report, we feel confident to project the performance data for the 76.5 and 86.5.

76.5

• 10 knot range of 2,500+ nautical miles
• “Fast cruise” speed of 34 knots
• Top speed 36.5+ knots

86.5

• 10 knot range of 2,700+ nautical miles
• “Fast cruise" speed 28.5 knots
• Top speed of 32+ knots

91.5

• 10 knot range of 3,000 nautical miles
• “Fast cruise" speed 28.5 knots *
• Top speed of 32+ knots *

* 2,400hp MTU engines

By comparison, the Sea Force IX line of performance sport fishing yachts go farther and faster, which means early arrival, less cost to operate and longevity of the engines. Not to be excluded is the extremely safe, stable, dry ride and the nimble maneuverability. Why sacrifice comfort and settle for a smaller vessel to get performance. The 81.5 will stand alone at the tournament level with its dynamic handling and agility against all competitors. Go ahead and slug it out with the elements and fish when other boats stay at the dock.

A winning bill-fishing client commentated after a turn at the controls during a sea trial, that the 81.5 "turns on a dime and gives nine cents change."

THE TRUTH ABOUT THE TANK

The Sea Force IX Management and Design team have long been proponents of tank testing as the best method for predicting the performance of their “Full Lifting” bottom geometry that is the foundation for the Force IX line of Performance Sport Fishing Yachts. Unlike the “Melting Pot” computer performance prediction programs that tend to “dull the data”, we prefer to take full advantage of our dynamic hull design by testing it on it’s own merits, prudently interpreting the information and properly applying it to achieve optimum performance.

Now it seems a lot of the competition have followed suit by advertising they have tank tested their hull designs. The real issue is what is done with the data the towing tank provides and that is where Sea Force IX takes yacht design and construction to the next level.

We combine the bottom geometry with our “Monolithic” construction methods and rigid weight-monitoring program under a comprehensive quality control umbrella. All the individual components are weighed prior to installation with locations recorded and tracked to assure the “all critical weight balance” optimized by the tank test data is maintained. This unique “performance tuning” process can only be performed by a company dedicated to the demanding rigors it requires. We are so dedicated and the result is a ride that must be experienced. We call it the “Ultimate Ride”.