Excess 13: understanding what truly drives a catamaran’s performance

What truly makes a catamaran high-performing?
Pure speed? Weight? Sail plan?

On the Excess 13, performance is not defined by a single figure. It is the result of an architecture designed from the outset to deliver true helm sensations, smooth sailing, and a safe, predictable behavior under sail. Optimized hull design, hulls developed with Marc Lombard Yacht Design, controlled weight, and a well-balanced sail plan: discover the key elements that make the Excess 13 a 40-foot catamaran resolutely focused on the pleasure of sailing.

Hull design: a key performance factor

On a multihull, most of the determining factors lie below the waterline.

The design is structured around three main principles:

• Reduction of wetted surface area
• Control of overall weight
• Optimization of appendages (keels and rudders)

With an optimized draft of 1.48 m (4’10”), the Excess 13 benefits from:

• More efficient keels upwind
• Deeper rudders
• More precise helm

A deeper rudder improves control and enhances the feeling of connection with the water.
The result: a more responsive, more predictable, and more enjoyable catamaran to steer.

By increasing depth for the same rudder surface area, the aspect ratio improves, which reduces drag and increases efficiency.

Asymmetrical hulls designed for sailing

Hull shape plays a key role in a catamaran’s performance. On the Excess 13, the hulls were developed in collaboration with Marc Lombard Yacht Design.

Their specific feature: an asymmetrical geometry with a well-distributed immersed volume along the length of the hull.

This technical choice enables:

• Better water flow management
• Reduced hydrodynamic drag
• Improved upwind performance
• Reduced pitching

Under sail, this translates into smoother glide and a more stable behavior in rough seas. Because the boat pitches less, it loses less speed with each wave and maintains its cruising speed more efficiently.

Weight: a key factor in multihull performance

On a performance cruising catamaran, weight (or more precisely, mass) control is strategic.

The heavier a boat is, the more it generates penalizing inertia.
The more optimized it is, the more responsive it becomes under sail.

Volume distribution designed from the outset

On the Excess 13:

• The center of buoyancy is positioned further aft
• The nacelle is more compact
• The mast is stepped forward of the coachroof and directly on the deck

This configuration allows for:

• A simplified structure
• Reduced overall mass
• Improved weight distribution

A catamaran’s performance starts with the balance between the center of gravity and the center of buoyancy.

Understanding catamaran weight: beware of calculation methods

When purchasing a performance catamaran, the stated displacement can vary significantly depending on the method used:

• Empty boat: empty displacement
• Light ship: light displacement
• Mid loaded: standard loaded displacement
• Heavily loaded: fully loaded displacement

The difference can reach up to 40% between a light boat and a heavily loaded one. These variations have a direct impact on performance.

As a French builder, Excess applies the European EEC standard to ensure clear and comparable information.

Deck and structural features

Platform clearance is often mentioned when discussing slamming.

In reality, this phenomenon depends on:

• The clearance between the nacelle and the water
• The geometry of the hulls
• The distribution of volume along the hull

On the Excess 13, the choice of trampolines—lighter than a solid structure—allows for:

• Reduced overall weight
• Less impact with waves
• Improved dynamic balance of the boat

Sail plan: a high-performance catamaran is one you can actually use

Performance does not rely solely on the sail area-to-displacement ratio.

It also depends on:

• The balance between the mainsail and the headsail
• Downwind sail options
• Ease of trimming
• Sail aspect ratio

An overly complex sail plan reduces the crew’s ability to fully exploit the boat’s potential.

On the Excess 13, the rig has been designed to be both efficient and accessible. The crew should be able to feel, trim, and handle the boat with ease.

In summary: what makes the Excess 13 high-performing?

A high-performance 40-foot catamaran is built on:

• An optimized hull design
• Hydrodynamic hulls developed with MLYD
• Controlled and well-distributed mass
• A nacelle designed to limit slamming
• A balanced and usable sail plan

The Excess 13 is not designed to deliver theoretical performance figures. It is designed to offer:

• True sailing sensations
• Precise helm feedback
• A lively sailing experience
• Consistent and controlled performance

It is this holistic approach that makes the difference.

And finally, the Excess team agrees that a high-performance catamaran cannot be measured in knots alone—it is recognized by the smile of the person at the helm.

Note: Weight, mass, and displacement are often confused:

• Weight corresponds to the mass of an object affected by gravity in its environment. An object always has the same mass, but its weight varies depending on where it is (on Mars, it would “weigh” three times less than on Earth, while its mass remains unchanged).
• Scientists therefore prefer to refer to mass, which is constant.
• Displacement corresponds to the volume of water displaced by the hull. It varies depending on the density of the fluid and the weight causing the boat to sink into it. This relates to Archimedes’ principle:
  “Any body immersed in a fluid is subjected to an upward force equal to the weight of the displaced fluid.”

For example, in seawater, your body will float higher if you fill your lungs—even though neither your mass nor your weight has changed.