"Ask us ANYTHING!!"

Answered


Boats...

Can you tell me how boats come to a stop ,while cruising in the water? or how
does a boat stop?

Gregg Orton
 

We thought the web viewers can have fun with this one. Due to the massive amounts of mail, I have decided to finally put this one to rest.  Here are most of the answers that we got from my e-mail box:

 

Abushnell wrote:

 

Re: Boats; no brakes

For power boats, it's easy: put the engine in reverse. Of course, the sensible way to do this is to put it in neutral, let the revolutions come down to a much lower level, and then put it in reverse.

For sailboats, well, you just gotta figure out how much momentum your boat has. An important part of learning to sail is learning to "depower" your boat. You drop your main or jib, turn directly into the wind, release your sails, backwind your sails, etc. All of these things will decrease the power your sails are extracting from the wind. But the boat will still move. After a while, you learn to judge how far your particular boat will coast without sails, and you drop your sails at a certain distance from your target accordingly. If you screw up, you either hit your target, or never make it there, at which point you take a lap and approach it again. I've taken 5 or 6 passes at an upwind dock while sailing an unfamiliar boat. If you wanted to get somewhere in a hurry anyway, you shouldn't have taken the sailboat.

Drew

 

Dave Varet said:

 

Boats dont stop unless you throw down the anchor, if they had parking brakes the anchor business would go belly up. Boats when not being artificially propelled by a motor float in the water and go the same speed as the current (minus the effects of friction) like a raft does. Since the boat is rather heavy the friction is large and the boat doesn't move that much in a straight line (it does move up and down as you can tell if you have ever been on an anchored boat in the ocean. What gives the impression of stopping is not breaking but the propulsion being ended. As nothing is fighting the friction to push the boat forward once the motor is turned off the boat is over come by the friction and slows down until it is back again at the mercy of the current. There you go.

 

Michelle threw out this comment:

 

Boats with breaks

I did a stint with the Army Reserves as a Bridge Crewmember (12C), and there we had breaks on our boats!!! The motors could be turned backwards with the pull of a handle, and then we'd gun the engine and stop on a dime (with the entire boat tipping forward in the process (Yes, we dunked the newbies by telling them to sit on the prow first :) hehehe )

Most boats only slow down due to the friction between the boat and the surrounding water. What you see though is that they don't really stop as fast as you think they do. If you are flying by on a speed boat, and then cut the motor, your body is thrown forward (you didn't have much friction with the air) while the boats slows down a bunch. But if you look at the froth on the dirty lake (I haven't been in clean lakes) you'll see you are still moving quickly. This is caused by develocitization, the tendency of your body to get used to a certain velocity. (Ever went from 100 MPH down to 65? You feel like you are crawling!!!!, but mostly you are too worried about the flashing lights behind you. :(

I hope this answer helps. I've had plenty of time on boats, and too many times in speeding cars.
 

Thank you,
Michelle

 

Carl Stones came up with this idea:

 

Answer.
It's the same with cars and aerodynamics. Big bulky cars have a problem
getting a high speed because of the air resistance pushing against it from
the front, whereas slick sports cars have less air resistance..
In the case of a boat, it's water, not air.
Jesus, even my DOG could have answered that one!

 

Spook uttered this:

 

While cruising the New York/New Jersey Waterway System so kindly provided for by the respective states, I was very careful to observe the things around me going on with the boat. I noticed a suspicious package alone on one of the Weehawken ferries, but more relative to the quetsion, I also noticed how the boats stopped and reversed. They actually slowed the engines to stop and then floored it in reverse to stop quickly (and believe me, they do stop quickly). To go in reverse, they just kept it going. To turn in reverse, however, they would put one prop in reverse and leave one stopped or spinning forward. This was a two prop setup though, so I'm not sure about other types, or what role, if any, a rudder would play in this scenario.
-Spook
 

Brian Schnierer articulated:

 

In response to "boats, no brakes"

just like with skateboards on asphalt. skateboards don't have brakes, but if you let them go on a level surface eventually they stop. that's the result of friction...amazing.

In the water boats experience a type of friction between water and boat, this is caused by the weight of the boat pushing into the water (thanks gravity, you big jerk) and some buoyancy (you know, the thing that makes fat people float) factors in there somewhere around the square root of ∏..or something...yeah, friction owns you.

 

Michael J. Falcone expressed this:

 

Boats with no breaks.
That is easy. you put it in reverse and the motor pulls backward.

 

Edwin Amirsaleh pointed out:

 

For the question as to how boats stop in water

When an object is put into motion, it stays in motion forever until acted upon by a force (one of Newton's Laws, but I can't remember which one - couldn't that bastard have given his laws better names?)

Of course, in our world forces that work against motion such as friction, drag, air resistance, etc. everything eventually stops, for example
- if you push a cart into motion and then leave it alone, it will stop because of rolling friction between the wheels and the ground
-if you throw a ball off a really high cliff, the ball will eventually loose its horizontal motion because of air resistance (I'm not saying that it won't hit the bottom - I'm just saying that it will stop moving forward and eventually just fall straight down in a perfect vertical path)

Final Thoughts; I have learned my lesson.  You guys slammed my e-mail box into a never ending spin, it was great, you have 45 unread message in your mailbox.  Keep the questions and answers coming.

Click here to send this page to a friend! Back to main page

2001 - 2002 Stupid Questions Answered