What Supplies Energy To Move A Sailboat? (Multiple Things)

Sailing is a lot of fun and there is nothing like it. When you are gliding across the water with the wind in your face, you get a feeling of surrealness. I love it more every time I am out there.

The force of wind and water on your boat’s sails and keel will supply energy to move your boat forward. The keel keeps your boat from drifting to the side and the sails give your boat forward motion. Different sails will work better in certain wind conditions for more energy.

Although wind and water give your sailboat power, let’s dive deeper into how they do this and how you can get more energy. First, let’s talk about wind types.

Wind Types And How They Affect Boat Movement

Sailing is one of the best experiences out there. The wind will become your best friend when you start sailing. When the wind is non-existent, you will be very upset at times, but just remember, the wind always comes back. There is a lot to the wind besides just wind. There are multiple types and certain amounts that are better than others. This section will talk about wind and what it is.

There are multiple types of wind when it comes to sailing. You have true wind (the speed of the wind when not moving). This is what the weatherman tells you on channel 5. If you go stand outside right now and don’t move, do you feel any breeze? If you do, then that is the true wind you are feeling.

Then there is apparent wind (the wind experienced while in motion). Imagine you are running into 10 mph of wind straight on, the wind feels so strong when you do this. If you stop running, the wind doesn’t feel as strong does it? When you are running and the wind feels way more powerful than 10 miles an hour, that is the apparent wind. Think of it as two strong forces going against each other.

This is what really affects your boat when sailing upwind. The apparent wind hitting your sails and boat will create a force that moves your boat forward. This will create more speed when sailing upwind. I love sailing upwind because it feels more intense. The wind is in your face, the boat is heeling over, and it just feels fast.

If you ever turn downwind after sailing upwind for a while, it is kind of disappointing. The big breeze in your face goes away, the heel of your boat will decrease, and it just won’t feel fast. The truth is your speed may still be good, but it’s harder to tell when traveling with the wind.

It’s clear that wind is a huge part of moving a sailboat. There are other parts that help move this boat forward though. Let’s look at keels next, and how they are helping with energy.

What Is The Purpose of a Keel? The Different Forces

The main purpose of the keel is to keep your boat balanced while sailing. If your boat is well-balanced, it will have more speed through the water. It will also help prevent your boat from drifting to the side when the wind is blowing.

Keels carry the ballast, which is a large weight. They can weigh anywhere from 100 pounds to 5000 pounds and sometimes even more. They are an essential part of your boat and sailing without one would be nearly impossible.

Take a look at the diagram below. It shows the wind pushing on the sails and how the force of the keel keeps the boat steady and on course.

As you can see from the images above, the sails are being pushed out causing the keel to be forced in the opposite direction. This is where the heeling would start to happen. The wind is pushing the sails to the starboard side and gives them lift, while the keel pushes in the opposite direction against the water. These two opposite direction forces, drive the boat forward because of its design.

The diagram below is of the same boat but with an aft view. This way you can see how the keel is pushed in the opposite direction causing the boat to heel. The keel pushes against the water or current to create its balancing force. The force of the keel against the water and the wind force against the sail sends your boat forward.

A side note to mention when talking about the keel and the water is current. The current can have an effect of energy on the boat’s motion. A current against the boat will definitely affect its energy. The more the current the harder it will be to sail into it. Sailing with the current is less drag making it easier to maintain the boat’s momentum.

As I mentioned before, all of these different forces are what drive the boat forward. The amount of force from the wind and water is what will allow you to have different speeds across the water. I won’t go into a discussion of a bunch of different sailing directions but I will mention one with a lot of speed. The beam reach is going to have a lot of force giving you good heel and speed.

Beam Reach Sailing

We talked about how sailing upwind is going to be better speed than downwind, but what about a beam reach?

Beam reach sailing is probably going to be your fastest point of sail. The boat is receiving the most force from the wind and water at this point, forcing your boat forward at optimal speeds.

When you are in a beam reach you can expect a good heel of the boat. The wind is lifting and filling your sails while the water is pushing against your keel and rudder.

These two forces working against/ together will create the best speed for the boat. See the Beam Reach area in the image below:

If you were going straight downwind, your sails would be full but it would be more of a pulling motion from your sails. You will not have that lift and help from the water against the keel and rudder. Think of it like this;

When you are in a beam reach the sails will fill up with wind and slightly lift the boat creating less drag. Now when you go downwind the sails fill up and just pull your boat along with more drag, not lifting the boat.

There is one more thing that supplies energy to move your boat and that is the boat’s motor. Let’s talk about that briefly since we all know how a motor works.

Motors And How They Move Sailboats

It’s pretty obvious how a motor moves a sailboat. It moves it like it moves all other boats, by propulsion. I won’t go into too much detail here since we all know how a boat motor works. There are a few things I want to mention though.

There are outboard and inboard motors. The outboard is mounted on the back of the transom and the inboard is inside the hull somewhere. They both have props that will propel the boat forward when in use. The speed of your boat will depend on the size of the motor and the size of the boat. If you are motor sailing you don’t need to go that fast. Motors are mostly for getting in and out of port, or moments when there is no wind. With sailing, you should never be in a hurry to go anywhere. Unless of course, it’s a race.

Just about every cabin-sized sailboat has a motor. Trying to back out of a slip with a 30ft sailboat with no motor would be almost impossible. They are a great help for navigating docks and ports. The only downside is they do require some type of fuel or electricity. It’s not a huge downside since you won’t be using it much, but the natural energy from wind and water is much better.

If you want to find out more about motors and how to attach them to your sailboat, check this article out!

In Conclusion

The wind, water, and keel supply energy and forces to move the sailboat forward. The engine is an exception in some cases, but the wind, water, and keel are your main components. The wind pushes against the sail and the sail harnesses the wind. While the sail works, the keel is below the water’s surface pushing against the water/current creating an opposite force. These forces compound together shooting your boat forward in motion. The more these two forces push the faster the boat will go.


Boatlifehq owner and author/editor of this article.

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