HI-PERFORMANCE BOAT OPERATION – PART 1: INTRODUCTION
It’s boat show season – the perfect time of year to check out the latest performance boats and Mercury Racing propulsion. For those of you who are about to purchase your first performance hull, congratulations!
With Winter in full swing, now is the time to review the basics of high-performance boat operation to ensure you and your passengers have safe experiences out on the water. We include a Guide to Hi-Performance Boat Operation with every engine we ship. We encourage new and current owners to review the book and then take in-boat driving lessons from your local high-performance dealer or boat builder.
Our operation guide is packed with general performance boating information, including propellers, hull types and overall boat performance. Let’s first review the various performance-boat hull configurations.
The traditional vee-bottom is the most common hull design. It offers good speed and a softer ride, especially in rough water. The softness of the ride depends on the angle of the “V” (called deadrise), radius of the keel line and the use of strakes.
If your boating is mostly in larger bodies of water such as the Great Lakes or open seas, you may want to consider a boat with this hull type.
The most recent change in this design over the past decade has been the incorporation of strategically placed notches or steps in the hull. The steps create air bubbles, raising the hull off the water on a drag-reducing cushion.
Some vee-bottom hulls feature a small flat area toward the rear of the keel called a pad. Similar to steps, the pad reduces the wetted surface area the hull runs on, increasing top speed with minimal effect on the ride quality. Mercury Racing offers a full array of outboard and sterndrive propulsion options for the vee-bottom boater.
Outboard tunnel boats are the fastest-turning race vehicles on earth. The sharp, 90-degree transfer where the tunnel sides meet the bottom of the sponsons helps the boat settle in the water as it enters a turn.
The submerged sponsons make the boat turn as if it were on rails. It is common for drivers to experience 4.5 to 5Gs as they enter a turn at 120 mph and come out at 90+ mph. Obviously, only experienced racers should consider this type of hull.
I like to refer to catamarans (or cats as they are often called) as tunnel boats on steroids. The design principal is similar. The boat rides on two sponsons or hulls separated by a tunnel. Air entering the tunnel generates lift as speed increases. The wetted surfaces and hull drag are reduced, for enhanced speed and ride quality. This design is not for the novice operator.
The air entrapment hull is sensitive to engine trim, wind, and water conditions. In general, they produce a smoother and faster ride over a vee-bottom in calm to mild chop. The vee bottom is king in rough water.
In Hi-Performance Boat Operation – Part 2: Rigging Fit & Function, I will review the important things to consider when preparing your new Mercury Racing outboard – or sterndrive-powered boat for the upcoming season.