Breaks are essential for automobiles, and they help automobiles to slow down and to prevent the risk of accidents. For any moving vehicle, it requires something (brakes) to stop the vehicle. But for the boat that moves in the water have brakes? Let’s find out.
Boats don’t have brakes because, in the water medium, it is not possible to stop the boat by increasing the friction between the boat and water as cars increase the friction between the wheels and the road. Something like that won’t possibly work with boats in the water.
When you press the brakes in cars, it stops because brake pads tightly grip the wheel rotors, cause a lot of friction, and restrict them from moving. The wheels stop because it causes friction with the road, and more friction means less speed until the car eventually stops.
And you can tell that something like this won’t possibly work in the water between the boat and the water. Most of the boats are driven by propellers or jet stream of water shot from the nozzle. And by stopping the propeller or impellers of the jet will not cause enough friction to stop the boat in the water.
Since there is less friction between the boat hull and the water, the boat will still move in the water due to inertia. That is why big container ships will travel miles in the water even after stopping the propeller. Because they are heavy and big so it takes more time to stop in the water.
But small boats are not like that; they move quickly and faster than the big boats or ships. Then you might think a small boat will stop quickly than big boats or ships; no, they won’t stop quickly in the water. Still, it takes time but takes only less time compared to big boats or ships.
Then how do boats stop in the water?
Now, you know that boats won’t have brakes to stop, and now you might be wondering how the boats will stop or slow down in the water without having brakes? Let’s find out how.
Boats stop in the water by rotating the propellers in the reverse direction. The boat won’t completely stop in the water just by turning the propeller in the opposite direction. It will still move in the water due to inertia. Next, by turning the boat a little bit sideways, it will stop in the water.
By doing those two things, boats will stop or slow down the speed in the water. However, it won’t decrease the speed immediately just by reversing the propeller rotation. Combining both the things (reversing the propeller and turning the boat sideways) will stop the boat quickly in the water. Now let’s see those things in detail.
1. Reversing the boat propeller will reduce the boat speed
If the boat propeller is rotated normally, then it pushes the water back and provides the forward thrust for the boat, so the boat moves in the forward direction.
If the propeller rotated reversely, it pushes the water in the forward direction and provides the reverse thrust, decreasing the boat speed. But by doing this alone will not reduce the boat speed immediately; still, the boat moves in the water due to inertia.
2. Turning the boat sideways
First, the boat propeller should be rotated in the reverse direction, and then by turning the boat sideways in the water will decrease the inertia and stops the boat quickly than just reversing the propeller spin.
And if you know or familiar with jet skis, the operator riding the jet skies will often turn the jet ski sideways to slow down the speed immediately. The same phenomenon is being used here for boats to reduce the speed or to stop the boat quickly in the water.
3. Some other ways (often seen in big ships)
There is one more way to decrease boat speed by increasing the boat’s wetted surface. But you will see this is on ships generally not on small boats. Stabilizer fins do increase the wetted surface of the ship and decrease the boat speed. Check Wikipedia on stabilizer fins for more info click here (opens in a new tab).
And one more thing is anchors cannot be used as brakes in boats. If you drop the anchor while the boat is moving fastly, then the boat will get wrecked because while driving the boat fastly if you drop the anchor, the boat will be pulled back suddenly if the anchor sets at the bottom, which may cause any problems for that sudden pull by the anchor.
By the way, if you are interested in the uses of anchors, check my article on Why do boats need anchors (opens in a new tab) to know the purposes and types of anchors in a detailed manner.
Overall, spinning the propeller in the reverse direction for reverse thrust and turning the boat sideways are the most common ways to stop the boat or decrease the boat speed. Stabilizer fins are mostly or often seen on ships, not on small boats.
How long does it take to stop or slow down the boat in the water?
The vast majority of maritime accidents occurred are due to the vessel(s) not being able to stop in time. It’s okay in big or open seas since you can see miles ahead, and you can stop, but in small or inland waters, the stopping time is crucial. It all depends on the stopping time of the boat or ship. Let’s see that.
The time taken to reduce the boat speed or stop the boat or ship, (all the way to the zero) will depend on the boat size and mass. If it is a big container ship, then it takes around 10 minutes to stop the ship completely—however, the time decreases drastically for small boats (less than a minute).
It is hard to tell how long it takes to stop the boat because the time depends on the boat mass and size. If it is a big ship, then it can take minutes to stop (all the way to the zero) the ship entirely. For small boats, it takes less than a minute to stop the boat completely.
Stopping time is one problem; another issue is with response time the skipper takes to stop the boat. The average time one would need to react and slow down the boat speed is more than 5 sec. And that’s not stopping time; it’s only a measurement of when the boat might begin slowing down from the time the operator first sees a potential danger.
According to the Lake expo website, the breakdown of that 5 sec time is based on the lead instructor for NASBLA’s (National Association of State Boating Law Administrators) boat accident investigation course.
- Boat operator response time = 2.5 – 3 seconds. This is the time taken by the boat operator to recognize the threat. And it depends on the experience of the boat operator and age as well.
- Reaching for throttle time = 0.5 seconds. This is the time taken by the boat operator to move the hand from the wheel to the throttle to push the throttle down to stop the propeller or for reversing it.
- Boat’s response time = 1 second. This is the boat’s time to respond to that throttle movement (from the helm (throttle) to the propeller at the stern of the boat).
The total time of 4 – 5+ seconds is taking for a boat to start slowing down the speed. If the boat operator is a bit experienced operator, then the response may decrease to 2 seconds.
The response time is high because in big lakes or oceans or seas, and if the waters are choppy or the weather is not right, it is hard to recognize the boat at a far distance (to identify the boat accurately).
Often big boats or yachts will appear as a smaller boat at a far distance, and the small boats will look like a normal-sized boat, but at a closer distance. So, it takes more time to recognize the boat, and an experienced boat operator will do it a bit quicker than a less experienced one.
And within that 5 sec, a 30 feet boat going a 50 miles/hr (80 km/hr) will travel another 324 feet (around) in the water. The boat covers a total of 324 feet distance before starting the slowing down process, which will increase the risk very much.
Since it takes a long time to stop the boat, the best option to avoid collisions is steering out of danger by changing the course. By doing this, the boat will always result in the quickest collision avoidance result.
Check this video on how long does it takes to slow down the boat (ship) speed.
Bottom line
Boats don’t have brakes, and to reduce the speed, the propellers are rotated in an opposite way producing a reverse thrust. By reversing the propellers and by turning the boat sideways will reduce the speed furthermore and quickly.
Big boats or ships will take more time to stop or reduce the speed, and small boat which goes at high speed compared to big boats or ships will take less time to stop or reduce the speed.