Navigation of boat using light house

Discussion in 'General Science' started by guru200773, May 18, 2010.

Apr 26, 2010
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How the boat gets is heading using the light frm the light house.. Pls explain me clearly..

2. mik3 Senior Member

Feb 4, 2008
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The driver of the boat sees the light and drives towards it.

3. beenthere Retired Moderator

Apr 20, 2004
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Maybe not too close, mik3 - the lighthouse marks something that is dangerous to run into.

4. mik3 Senior Member

Feb 4, 2008
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Ok, I meant use it to find his orientation and not drive the boat exactly towards the light house.

5. retched AAC Fanatic!

Dec 5, 2009
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The boat navigator has a map that shows the lighthouse locations as well as other landmarks and stars and such. When they see the lighthouse, they align the map with it to get their bearings.

Some lighthouses are used to mark dangers, like sand bars, shallows, and rocky areas.
Some lighthouses are used to show the way to port for use in fog and rain and at night.

When there is more than one lighthouse or buoy. The lightkeeper changes the color of the light.

Green means pass the light on the left side of the boat
Red means pass the light on the right.

If there were huge rocks, they would put a light on the left and right, so you wouldn't run into them in the night or bad weather.

6. Markd77 Senior Member

Sep 7, 2009
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They flash at different rates and patterns so you can tell which lighthouse it is if you have the right chart (over here anyway).

Apr 26, 2010
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My sir taught me that light house emits a omni directional pulse of light every time the beam is pointing towards due north.. If the speed of rotation of the beam is known a distant observer could record the time interval between seeing the omni directional flash and seeing the beam and hence they calculate the bearing of the light house.. But i asked him that how they calculate the bearing he said i don know.. Thats y i posted a thread here now tell me any one knows how they r calculating the bearing by recording the time interval between seeing the omni directional flash and seeing the beam...? Pls explain me

Feb 4, 2008
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9. retched AAC Fanatic!

Dec 5, 2009
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Lighthouses no not point light in any particular direction.

If the lighthouse was in the southern shore of a landmass, the light would flash into the landmass, not being seen to the navigator.
During Rising and falling seas, lighthouse lights appear to flash when on constantly, but that is optical interference.

They do flash, but that is in all directions, to distinguish which lighthouse it is.

http://en.wikipedia.org/wiki/Lighthouse

Apr 26, 2010
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thanks friends

11. loosewire AAC Fanatic!

Apr 25, 2008
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Most light houses no longer operate,some are endangered.
Some have been moved for protection. A search of working
light houses should be made. It hard to tell,the park service
has taken over a lot them. No longer needed with all the
electronics. Check It out,If you are positive report working
location to be sure you have to see light at nite.Good subject
(guru),you are doing good by posting.

Last edited: Jun 1, 2010
12. loosewire AAC Fanatic!

Apr 25, 2008
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Saw a story about family in south pacfic on sail boat was rescued
by setting off rescue beacon.The U.S. received beacon contacted
nearest country to sent jet ,backed by helicopter.all Five members
survived.of family.That the way they do It now,you can be safe any
In the world with a beacon.

13. loosewire AAC Fanatic!

Apr 25, 2008
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Keep It going Guru,post.

Apr 26, 2010
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ya sure looose wire

Apr 26, 2010
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that story is really interesting hmmmm... luck also favors sometimes

16. teno45 New Member

Jun 2, 2010
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I know what your talking about here, and i'll try to give a rough explanation on how it works. I am not saying this is how all lighthouses work, or anything like that. I am just trying to explain how this system the OP is talking about works. It is similar to the concept of VOR (VHF omnidirectional radio range) Navigation systems on aircraft).

The easiest way to think of it is with two lights. One unidirectional light (that shines in all directions) and one directional light that rotates at a set speed. When the rotating light points to true north, the unidirectional light will flash. then the rotating light with do one full rotation. then the unidirectional light will flash again. and this continues indefinitely.

Now, lets assume that the rotating light takes 60 seconds to do a complete loop. If you see the flash, then it takes 30seconds for you to see the rotating light pointing right at you:

60seconds (total rotation) / 30seconds (time since flash) = 2.

360 (degrees on a compass) / 2 (from previous equation) = 180(degrees).

This says you are 180 from north(ie: SOUTH), FROM the lighthouse. ie: you are directly south of the lighthouse. and the light house is directly north of you.

If you see only one flash, then you are directly north of the lighthouse.

Hope this helps.