lat and long of buoys - where available?

[Burnham Bob]

Some pilot books have lat and long of buoys they use as way points but when i'm plotting a course at home, is there anywhere i can look up the lat and long of a specific buoy? Currently I estimate it reading the co-ordinates off the chart

google doesn't seem to help much as i get loads of unsorted sites

 

[sarabande]

doesn't the Admiralty List of Lights have them ?

http://www.ukho.gov.uk/ProductsandServices/DigitalPublications/Pages/ADLL.aspx


The last time I had a copy was when charts were black and white.....


Some in the Solent
http://www.winningtides.co.uk/pages/buoyracer.htm

Some E coast ones here
http://www.eastfarleighcruisingclub.co.uk/page39.htm


Try searching for "buoy waypoints". I use Altavista BTW.

 

[alant]

Some pilot books have lat and long of buoys they use as way points but when i'm plotting a course at home, is there anywhere i can look up the lat and long of a specific buoy? Currently I estimate it reading the co-ordinates off the chart

google doesn't seem to help much as i get loads of unsorted sites

Mcmillan Reeds Almanac's have them in front of each section.

Don't forget to adjust for height of tide

 

[Skysail]

Reeds certainly have them; make sure you offset the waypoint a few hundred yards in case another boat is using the same waypoint .....

 

[Euphonyx]

Some pilot books have lat and long of buoys they use as way points but when i'm plotting a course at home, is there anywhere i can look up the lat and long of a specific buoy? Currently I estimate it reading the co-ordinates off the chart

google doesn't seem to help much as i get loads of unsorted sites

Here's a list of everything that floats, blinks and whistles, bangs and bongs off the Irish coast:

http://www.commissionersofirishlights.com/cil/aids-to-navigation/definitive-list.aspx

I presume that Trinity House have a similar resource. Try here for starters:

http://www.trinityhouse.co.uk/aids_to_navigation/the_task/floating_aids.html

 

[l'escargot]

...make sure you offset the waypoint a few hundred yards in case another boat is using the same waypoint .....

But if everyone does that they will all hit each other a few hundred yards away from the buoy! Best just put in the buoy and keep a look out when you get near so that you can avoid any other boats in the vicinity.

 

[Solitaire]

Currently I estimate it reading the co-ordinates off the chart

google doesn't seem to help much as i get loads of unsorted sites

Why "estimate" of a chart? It will give you the right lat and long if you use the correct scale chart - but DON'T put the exact position in as a way point. You will either hit it or everybody else will converge on the same point if taken out of the almanc.

 

[2nd_apprentice]

I just upload them from my laptop chart plotting software.

 

[guernseyman]

Reeds certainly have them; make sure you offset the waypoint a few hundred yards in case another boat is using the same waypoint .....

...that's OK...until it's foggy (or dark and the buoy is not lit) and you are approaching the buoy in a direction in line with your offset position.

Much better to know where the buoy is, and avoid it.

 

[Burnham Bob]

the reason i said 'estimate' is that reading off the chart is a cumbersome and time consuming method and whilst it's accurate enough for navigation it's a chore

much easier to get a list of coordinates to enter on the gps, and as for hitting buoys its never happened so far as with tides and wind its unlikely that the buoys are exactly places to the second and anyway i always keep a lookout

 

[Little Rascal]

...a cumbersome and time consuming method and whilst it's accurate enough ...

...much easier to get a list of coordinates to enter on the gps...

Just check and double check that you have entered correctly! I was told that the RAF have two people on this job at a time... so easy to get a number wrong. At least with the chart there is a visual reference too...

 

[Robin]

None of our wpts are exact buoy positions, for the simple reason that, assuming zero visibility worst case scenario, a) we don't want to be headed straight for a large chunk of metal, they have sharp bits (don't ask) and b) we want to be able to approach many of our wpts from a variety of directions and know that the wpt is in clear water on that approach as is the track to the next one. Channel wpts therefore are placed on straight line tracks in the centre of the channel and will either be abeam of a single buoy or mark or better still between two such buoys. Our GPSs were radar linked to display on the radar screen in a 'lollipop' so that the buoy or buoys should be seen on the radar next to the 'lollipop' thus distinguishing them from an echo that might just be Fred out fishing in the rubber duck.

 

[BlueSkyNick]

100% agree.

But if everyone does that they will all hit each other a few hundred yards away from the buoy! Best just put in the buoy and keep a look out when you get near so that you can avoid any other boats in the vicinity.

I much prefer to know the exact position of a mark and aim to miss it, than to try and recall how much room for error I programmed in some winter months previously.

 

[l'escargot]

...that's OK...until it's foggy (or dark and the buoy is not lit) and you are approaching the buoy in a direction in line with your offset position.

Much better to know where the buoy is, and avoid it.

The poster I responded to said offset it "in case another boat is using the same waypoint". It is a fallacy that all boats heading for the same waypoint will hit each other otherwise they would all do so when heading for any common point such as a harbour or marina entrance - they don't, they all take steps to avoid each other.

More important than off setting a waypoint is to keep a sharper lookout as you approach your destination as there will always be converging boats be it a waypoint or any other point of navigation.

 

[l'escargot]

I much prefer to know the exact position of a mark and aim to miss it, than to try and recall how much room for error I programmed in some winter months previously.

I agree. Far better to know where it is rather than just that it is in the general vicinity. We always aim for the harbour entrance rather than a few hundred yards away from it and keep a good look out.

 

[sarabande]

Burnham B - one second in a Lat/Long position is not far off 90 feet.

It's pretty self evident that bouyage in a channel is laid to a more precise position than that, and even the big ones in the Channel, laid by Trinity House to what is called an "Assigned Position" have a position which is known to a thousandth of a minute (e.g. Latitude 51° 03'.653N) which is about 6ft. Without going into some slightly abstruse maths and technospeak about geodetic datums, that should be enough to help you know where you are.

It is, as others have noted, generally prudent to adjust any buoy's waypoint to that side of the mark which has the deeper water, but even that will not mitigate the consequences of joining two waypoints which are on either side of a drying sandbank, and trying to sail along that line which joins them.

 

[alant]

I agree. Far better to know where it is rather than just that it is in the general vicinity. We always aim for the harbour entrance rather than a few hundred yards away from it and keep a good look out.

And if you miss it?

Which side of the entrance are you then?

Much better to plan an offset, then when you get close to the shore, you know which way to head to get to the entrance.

 

[l'escargot]

And if you miss it?

Which side of the entrance are you then?

Much better to plan an offset, then when you get close to the shore, you know which way to head to get to the entrance.

So it is better to aim to miss the harbour entrance and then correct the self imposed error? If I am approaching the entrance to Portsmouth Harbour from the east, which would be better to aim for using your technique, halfway down Haslar wall or the Southsea War memorial?

Using your argument, what if you then miss the point you have offset, which side of it are you? You could end up further from where you want to be or you could even by accident end up exactly where you want to be.

No thanks. I will continue to navigate to where I want to go, not some random place near by, and when I get close use pilotage. I have always got there using this method and have managed not to hit anything on the way.

 

[Burnham Bob]

Sarabande I'm fascianted to know how they keep buoys within six feet (I don't doubt your word for a inute!) but if the tide goes up and down they must have some way of being anchored to the bottom and at low tide can swing about more than at high tide.

If you can spare me the maths I'd be delighted to know how they overcome that as my East Coast pilot books warn that cans can sometime get blown over the shelf they mark

 

[alant]

Old & trusted method, used even by helicopter pilots

So it is better to aim to miss the harbour entrance and then correct the self imposed error? If I am approaching the entrance to Portsmouth Harbour from the east, which would be better to aim for using your technique, halfway down Haslar wall or the Southsea War memorial?

Using your argument, what if you then miss the point you have offset, which side of it are you? You could end up further from where you want to be or you could even by accident end up exactly where you want to be.

No thanks. I will continue to navigate to where I want to go, not some random place near by, and when I get close use pilotage. I have always got there using this method and have managed not to hit anything on the way.

Its not my "argument", simply a tried & trusted method of getting to a harbour when making landfall, used by mariners for generations, before GPS & other gizmos existed.

"Though the concept of "off-course navigation" (steering to one side so you know which way the error is) is probably as old as navigation, Chichester was the first to utilize it in a methodical manner in an aircraft. His only method of fixing his position was to take sun sights with a sextant. This was a difficult thing to do in a moving aircraft which the pilot was also required to fly the aircraft at the same time. After the sun sight was taken he then had to make calculations by long-hand. As all this could be unreliable he needed an alternative. When he reached a point at which the sun angle was at a pre-calculated angle, the pilot then made a 90 degree turn to the left (or right as pre-calculated) and then flew along this line until the island was reached. The advantage of this method was that the effects of drift were reduced to errors in distance travelled, usually much smaller. The technique allowed him to find tiny islands in the Pacific. He was awarded the inaugural Amy Johnson Memorial Trophy for this trip. Chichester then decided to circumnavigate the world solo; he made it to Japan; but, on take-off from Katsuura Harbour Wakayama, he collided with an overhead cable, sustaining serious injuries."

Also, http://www.associatepublisher.com/e/o/of/off-course_navigation.htm

The Solent is more pilotage than navigation, so not really worthy as an example.