What Influences Sailboat Speed
Sailboats have different shapes and sizes, and different sailboats can reach different speeds. There are many internal factors, such as those related directly to the boat, and external factors, such as weather, ocean currents, etc., that influence the speed of a sailboat.
Boat Size and Length
The most crucial thing that plays a role in speed is the sailboat's length and overall surface area. What does size have to do with speed, you ask? For a sailboat to go fast, you need to maximize the propulsion by the wind and keep drag and resistive forces to a minimum.
As the sailboat moves through the water, it generates waves. One wave that is created among others constantly rides with the boat. It has its peak just in front of the bow, while its trough is at the stern. If this wave is long enough, it can act as a wall of water to the boat.
The aerodynamic shape of the bow is designed to push up and rise above this wave. This allows the boat to lift the bow out of the water and rise above the water surface. As the bow rises, the stern gets pushed down into the water. This reduces the drag and also allows the boat to glide above waves.
But this wall of water creates resistance for the boat, and the sailboat requires power and momentum to break through this resistance. A larger sailboat has more momentum, which allows it to break through the barrier easily. This makes it possible for the larger boat to go faster.
You might think that a smaller boat is lighter and will offer less resistance and drag. Yes, this is true, but a smaller boat generates multiple small waves, which offer more resistance. Lightweight boats are also more susceptible to wind shear and tend to veer off course.
Hull Shape
Different boats have different hull designs. The hulls are designed to be narrow and precisely engineered for racing sailboats to offer minimum resistance. It makes sense that a boat with a hull like a bathtub will not even come close to a sailboat with a narrow and streamlined hull.
The hull design also plays a vital role in the speed of a sailboat. A hull built for speed will have a straight line from the lowest point to the aft, and the aft will be wider. This design makes the boat stable and allows it to reach higher speeds.
On the other hand, a boat with multiple curves on the hull and a narrow transom will not be as fast. The reason for the hull playing a vital role in speed is simple. It needs to cut through the water to ensure the least resistance.
There are three major hull types for sailboats.
Monohull
As the name implies, monohull sailboats comprise one hull. These boats offer high levels of stability, making them extremely difficult to capsize. The hull is designed to cut through the water, which keeps the boat stable, and allows it to pick up speed. The hull can be raised out of the water if you need to go faster. Monohull boats are traditionally designed to sail below 10 knots.
Catamarans
A catamaran, more commonly known as a cat, comprises two hulls running side by side. These hulls are similar in size. Cats are significantly faster than monohulls and can reach between 15 knots and even go more than 50 knots.
Trimaran
The Trimaran is also known as the double outrigger. Trimarans have three hulls, which means they offer more stability and are extremely buoyant. The three hulls allow the boat to gain speed because it rises above the water surface with little resistance. Tamarans can reach speeds of up to 20 knots.
Skill Level
Sailboat racing has become a highly competitive sport. When it comes to speedboats, you can use engine power to hit maximum speeds, but it takes a lot of skill and experience to get your sailboat to move at speeds three times the wind.
The amount of training, skill, and experience you have is crucial to how fast your racing sailboat goes.
Winds
The only propulsion you have on a sailboat is the wind. With a good wind in your sails, your boat will move much faster. Both types of winds, apparent and true, play a crucial role in your sailboat's performance. The stronger the true winds, the faster the boat will move.
Waves
Waves play a crucial role in your boat's performance. They influence the speed and determine your and your vessel's safety. Calm and serene water can quickly turn aggressive and furious without prior notice.
If the waves are strong enough, and you don't know how to navigate through them, they can easily capsize your boat. Depending on their direction, they can also significantly increase or decrease the speed of your sailboat.
When the medium you are running on, water, is moving fast, your boat will experience a significant increase in speed. You can think of it as walking on a travelator. If you are walking in the same direction as the travelator, your speed will be increased. But, if you decide to walk in the opposite direction to the travelator, you will look weird and will be considerably slowed down.
Going Faster Than The Wind
Two types of winds influence the speed of a sailboat; these are true wind and apparent wind. To understand these better, let us look at an example. Imagine you are riding a motorcycle when there is no wind. As you pick up speed, you begin to feel the wind in your face; this is called apparent wind. It is the air pressure you feel while moving through the still air.
Say you are riding at 20 mph on your motorcycle; the wind you will feel on yourself will be 20 mph. Now let's add true wind to the equation. Say the wind is naturally blowing at 20 mph, and you are heading in the same direction as the wind. The wind pushing you and the apparent wind will cancel each other out if they are perfectly reverse-parallel to one another.
The sails experience the same apparent wind you felt while on the motorcycle when you are on the sailboat. The sails are designed to put the apparent wind to use and help propel the boat further. As you increase your speed, the apparent wind grows stronger, which leads to more wind in your sails.
How Fast do Racing Sailboats Go?
Now that we know the factors that influence sailboat speed, let us look at how fast racing sailboats go. If you are a traditional sailboat sailor, you will be lucky if you can hit 10 knots. But with racing sailboats, you can achieve over 15 knots, and many racing sailboats can hit 20 knots. The fastest anyone has ever achieved on a sailboat is 65.45 knots, a world record.
