Sailboats are one of the famous boats, and it symbolizes journey and adventure. They also are associated with being carried along by the “breath of life,” as its primary form of momentum is gained through the wind in its sails. Now, let’s see what else power the sailboat and whether they have motors or not.
Sailboats have motors, but not all sailboats have them. Nowadays, most sailboats are using electric motors rather than traditional diesel or gas ones. Motors on sailboats are mostly used during an emergency or at the marina, and generally, no one uses them often or for regular sailing.
All sailboats will not have motors; only some will have motors, and generally, if a sailboat exceeds some length (maybe 6 or 7 meters), it will have a motor in it. People will often not use these motors; they will use the sails to move in the sea or ocean.
Mostly motors will be turned off while sailing because if the boat is moving in the water with the help of sails, then turning on the motor and increasing the propulsion will not increase the speed much; instead, it will cause some slightly concerning sounds and fuel wastage.
A sailboat with motors is known as Motorsailer, which is typically a pleasure yacht, that derives propulsion from its sails and engine(s) in equal measure.
Wikipedia
Why does a sailboat need a motor if it has a sail?
After knowing that some sailboats will have motors, now, you might be wondering what is the use of the motor in a sailboat without using it while sailing in the water.
The main use of a motor in a sailboat is for docking the boat at the marina or to move in the water if there is no wind. Some marinas banned the use of sails in the marina because solely docking the boat with the wind at a marina can cause any damages if the wind suddenly changes or decreases.
From the above picture, you can see how the boats are closely packed at the marina, and if a boat is solely docked in the marina with the help of wind and if the wind increases, then the boat can hit other boats on its way and can cause any problems for others.
And if the wind decreases while docking, then the boat can’t move in the water, and it can cause any problems for the other boaters who are moving in or out of the marina.
Due to these issues, many marinas banned the use of sails in the marina in recent years, so sailboats are pretty much forced to have an engine. It is happening because we are not controlling the boat, with the help of wind we are controlling the boat. So, entirely depending on the wind can cause any damages.
So, if the boat has a motor, then you can dock the boat quickly and easily without causing anything bad. That is one of the reasons why sailboats need motors. And the other reason is that if there is no wind, you can’t move in the water.
All the time, we cannot presume that there will be some wind to carry the boat. Sometimes if you are in a hurry and if there is no wind to sail or move the boat, then it is hard to move the boat. So, sometimes having a motor in the boat will help a lot.
Are motors on a sailboat the same as normal boat motors?
Now that you understand the motor’s uses in a sailboat, you might wonder if we can use the same motor (outboard or inboard) that is used on a normal boat for a sailboat.
Motors on a sailboat are the same as normal boat motors (outboard or inboard), but only diesel or gas motors are the same. And electric motors are much bigger in size than compared to the normal boat electric motors because big boats require more power, so they are big.
Typical sailboats have a small, either outboard motor attached to the transom, or an inboard, that has a sterndrive. Up until 1870, there were no motors on a sailboat. And not many had them until the 1930s (source). Today most sailboats over about five or seven meters in length have a motor.
Most smaller sailboats will have long shaft outboard engines, and some of them will be mounted on the stern. Larger boats from 26–27 foot onwards will have an inboard motor with a reversing gearbox and either a straight shaft in older boats or a Sterndrive in most modern ones.
Nowadays, electric outboard motors are becoming more popular than diesel or gas ones in sailboats, and these are a little larger than a trolling motor. Since most sailboats have solars on it, so having an electric outboard will benefit it a lot.
It is beneficial to have two batteries, along with a solar/wind charger. With this set up the range could be as high or higher than a gas or diesel motors if used sparingly and gently. A single battery will have an approximate range of 30 NM (55 km) with a 15 hour charge time (source).
Italian explorer Christopher Columbus set a world record in the late 1400s by only sailing with the wind.
History
How fast can a sailboat sail (travel) without a motor solely on a sail?
Sailboats are known to its maneuverability to sail normally along with the winds, and mostly, it won’t go fast. Let’s see how fast a sailboat will travel solely on the wind.
On average, most sailboats travel at around 5 or 6 knots (roughly 6 miles), and on average, most sailboats can achieve a full speed of 8 knots (around 9 miles). However, they can’t exceed the hull speed so that the speed will vary for each sailboat.
However, many factors will affect boat speed, such as wind conditions, current, and many other factors. And with the increase in the sailboat length, the hull speed (top speed) of the boat will increase.
The maximum speed (Hull speed in knots) comes from the formula 1.34 times square root of the waterline (in feet). Waterline is the boat’s overall length (from bow to stern) that is submerged in water.
If the waterline length is 25 feet, then the boat’s maximum speed (hull speed) will be the square root of 25 times 1.34, which is equal to 6.7 knots. Meaning the maximum speed of the boat, which it can travel is 6.7 knots per hour. Still, you can try increasing the speed by removing the extra weight in the boat, and design also changes the speed.
With that being said, the boat speed also depends on its overall length, so the top speed (hull speed) will vary for each boat if the boat length varies. And the other factors such as wind conditions and current will be the same for many boats.
These are some of the factors that affect boat speed, and there are some more factors as well. Check my article on Essential factors that affect the boat speed (opens in a new tab) to know how the hull design and different types of water will affect the boat speed.
Bottom line
Sailboats have motors, and although not all the sailboats will have motors. Among all the types of motors nowadays, often sailboats use electric outboard motors rather than diesel or gas motors.
The motors are used to dock the boat at the marina or to move the boat if there is no wind. One of the main reasons is why they have motors is nowadays many marinas have banned the use of sails in the marina in recent years because it can cause any damages (disturbances) if there is no wind or less wind.