Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > General Cruising Forum
Cruiser Wiki

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 08-12-2009, 04:26 AM   #43
Admiral
 
MMNETSEA's Avatar
 
Join Date: Oct 2004
Posts: 3,067
Default

Osirissailing.

The statement :-

"Most nautical charts in the world were geographically last updated 40+ years ago to as much as 200 years ago in some places in the world." is at the best misleading and at the worst patently false.

The Members Of the International Hydrographic Organisation continuously update their nautical charts and issue Notices to Mariners regarding those updates.

The United Kingdom Hydrographic Office for example produce annually thousands of updates and publish these in Notices to Mariners : check HERE

The Australian Hydrographic Service also continuously update their charts: HERE

The United States Government clearly sets out their objectives in providing Notices to Mariners with corrections to charts :- HERE

The continuous need for charts that are up-todate as is possible, is not only the result of natural causes, eg: siltation, floods, tsunamis etcc, but also the increasing need to reclaim land from the sea. Here is short list of where the geographic boundaries of coastlines and harbours were changed, resulting in major changes to nautical charts for those areas :- HERE

Just two from the above list, ie: Hong Kong and Singapore, where one has the largest container port in the world, the other having one of the world's busiest sea lanes.

The above man made changes do not include underwater hazards such as wrecks and cables etc.. These are Notified to Mariners continuously, in order that charts may be annotated appropriately or renewed..

The other statement :

"So GPS and charts get you to the vicinity of your destination, but it is your eyeballs and your brain that get you safely into harbor."

Unfortunately, neither your eyeballs nor you brain can penetrate the depths to ensure the safest approach and entrance into the harbour itself. The updated chart or a notice to mariners will show the underwater topography and any other listed hazards such a a sunken wrecks, rocks, shoals etc.

---

This statement :

"I like baiting Sextant folks as much as I like baiting Learning Latin folks - it's easy and only done in the spirit of good natured debate and fun."

'Baiting' might be easy and fun, for some people. However, if it is directed at those who are at the early stages of learning the ropes of cruising; then the practice can be said to be of little value.
__________________

__________________
MMNETSEA is offline   Reply With Quote
Old 08-12-2009, 05:47 AM   #44
Moderator
 
redbopeep's Avatar
 
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,185
Default

Hi, there,

Ummm....I seem to say ummm alot with your writeups osirisailing...LoranC IS going away but your presentation of the information is quite misleading. That doesn't mean Loran is going away! E Loran (better than LoranC) is the replacement. And, yes, funding is always an issue for any government program... but MORE RECENT updates about Loran are available via the following links. Let's not mislead our CL cruisers with outdated information or confusion about LoranC vs E Loran. Its like you said "Broadcast TV is going away!" when the accurate statement this year in the USA would be that HDTV is the "new and better" broadcast TV and NTSC TV is no longer supported.

http://www.insidegnss.com/node/1615

http://www.boatus.com/gov/LoranUpdate09/

http://www.loran.org/

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

I have not had the opportunity to use CN on long passages--unfortunately, my sailing to date has been coastal--while I have a few decades of experience none of it is crossing oceans (soon to change as we've just completed a rebuild and are beginning sea trials on our "cruising" boat . So I cannot speak with personal voice regarding it's utility on long passages--and since it seems that you cannot either I guess we're together in that boat However, I do know many cruisers who have employed CN with great results. In this thead I've mentioned that before. These are folks I am close to and whom I trust. There's a (30 year) experienced cruiser whose boat sits adjacent mine right now--he teaches CN, he uses CN, and has many stories of its utility on his 30 years of cruising everywhere from the US east coast to Bermuda to the Caribbean thru the Panama Canal up and down the West Coast, to Hawaii...well, pretty much every where he goes he uses CN and RDF as a matter of fact... I don't even know if he has a GPS...There are many, many, many cruisers with great success using CN. True--most were cruising in the 1970's and 80's when having a GPS and even a good radio wasn't as likely as it is today. But, that doesn't mean they were not successful--they were. Your off topic comments about lack of utility of CW and the US Coast Guard's use of DSC? There's a whole world out there besides the USA, you know.

Clearly, from your statements, you have not successfully employed Celestial Navigation during your travels. It's OK and your own choice. For whatever reason that you choose, it's fine that you don't use CN. Any newbie that tries to use CN will learn whether or not they are able to employ it for navigation. Lucky for us today, we do have GPS, Loran, RDF...all to assist us in our navigation, therefore, it is possible for someone (who wants to use it) to learn Celestial Navigation and check their progress and improve over time given the other navigation tools available. Please, I'm asking that you do not impose a negative view of a navigation method where negativity is not needed.

Fair winds,
__________________

__________________
"Do or do not. There is no try." - Yoda

What we're doing - The sailing life aboard and the Schooner Chandlery.

redbopeep is offline   Reply With Quote
Old 08-12-2009, 06:10 AM   #45
Admiral
 
Nausikaa's Avatar
 
Join Date: Sep 2005
Posts: 1,619
Default

As one with years of experience in using celestial navigation (ex. merchant navy navigating officer) I can certainly vouch for the workability and accuracy of celestial navigation within certain parameters; these being primarily the quality of the horizon and the ability of the user as well as the need for accurate time except for noon sights.

There is no one system of navigation which is infallible. A sextant can be damaged; a GPS can fail or suffer from other factors affecting its accuracy; RDF always was a poor system, LORAN only gave a good indication as to one's position; SINS was good but so expensive it was only used on nuclear subs and major warships, DECCA was good but only usable within 200 NM of the coast in certain areas of the world, etc.

Some navigational systems are better than others. This has always been the case and always will be but the prudent navigator recognises this; but all systems are merely aids to navigation.

The art of navigation is not so different from the job of an intelligence service. All available information should be gathered using ALL available systems, the information examined and assessed for accuracy and errors and thereafter a careful analysis made to indicate the vessel's believed position.

The dangerous navigator is the one who knows exactly where he is. The good navigator is the one who from a believed position navigates with caution and care.

Navigation is not about criticising one system whilst applauding another. It is a matter of common sense.

Aye // Stephen
__________________
Yacht NAUSIKAA | Call Sign: 2AJH2




WHEN WAS THE LAST TIME YOU DID SOMETHING FOR THE FIRST TIME?

www.nausikaa.org.uk

= Sweden, Norway, Denmark, Lithuania
Nausikaa is offline   Reply With Quote
Old 08-12-2009, 06:14 AM   #46
Commander
 
Join Date: Mar 2007
Posts: 130
Default

Please - you are reading the headlines - not the body of what is actually happening. And what you are saying is PATENTLY false and Misleading because it only repeats the headlines not the reality of the life in the current world of nautical navigation. Here is an except from the required User Agreement you MUST acknowledge before you can download any NOAA/NGIM charts >>>>

While NOAA has accuracy standards for each step in the data collection and chart production process, much of the depth information found on NOAA charts is based on surveys conducted before 1940, the shoreline is more than 20 years old, and paper charts used to be compiled manually.<<<

And that is the TRUTH right from the "horses (or NOAA's) mouth.":

The critical question is - What are they updating? I have talked face to face and discussed this subject with actual NOAA/NGIM personnel - not their P.R./legal departments. There have been NO updates of geographical data and soundings in the USA chart system except for major commercial harbors. There are constant updates to moved or relocated major harbor channels and markers/bouys when reported by USCG or USCoE. Simply put by the staff of NOAA/NGIM there is no money to do it.

The "200 years" is from DMA (now NGA) charts of the South Atlantic and South Pacific areas. The NGA also publishes a disclaimer about the accuracy of their charts.

Speaking of the South Pacific, you of all people should know that there is a huge amount of "uncharted" reefs, atolls and other hazards out there. That is why the Penniped Waypoints (17 pages) and South Pacific Waypoints lists are critical to safe navigation in the South Pacific. When it comes to governmental charts and charting, the rule of thumb is quite simple - if no commercial shipping goes there or through the area, the data is not present or updated very often, if ever.

New people to cruising need to know that there are huge gaps in the charts and databases of published nautical charts. And it is prudent and wise to search out other sources of information for an area such as cruising guides, cruising associations newsletters like SSCA or Latitude 38 and many others around the world. Relying solely on government sources is naive and hazardous to your health.

I know that the French are quite good at keeping their nautical charts reasonably up to date for their islands and areas. I do not use Admiralty Charts or Australian Charts so I cannot speak to their actual policy on updating geographical and hydrological data. It all comes down to money and budgets, if the government does not have the money, they start cutting out services to citizens and guess who is at or near the top of their "outdated," not necessary, and doesn't have any lobbyists lists?

Your statement >>Unfortunately, neither your eyeballs nor you brain can penetrate the depths to ensure the safest approach and entrance to a harbour. The updated chart or a notice to mariners will show the underwater topography and any other listed hazards such a a sunken wrecks, rocks, shoals etc.<< is also patently false and misleading at best. Since there is no updating of hydrographical or topographical information on the chart except in major commercial seaports, and the "lag time" between receiving a notification of a hazard and its being published as Notice to Mariners or Chart Correction is substantial - I would be extremely careful of believing that those wrecks, rocks, and shoals are there or not there or that they are the only hazards there and any new ones are absent. Which is why I have scanning sonar and polarized sunglasses so that I can see what is down there under the water if it is clear enough and by sonar if it is not. By watching the action of the water flowing around obstacles you can "see" what is down there. All that is done by eyebals and brains. You may wish to enter a harbor with your eyeballs and brain closed and trust the "updated" chart - but I would not recommend it to anybody wishing to have a long and enjoyable life on the seas. Your eyeballs can see the water, see the coastlines, see the shoals, and see wrecks and other obstacles (subject to water clarity). Your brain interprets what you see to indicate possible hazards. Or as they say in the Bahamas - you have better be able to "read the water." Sand bars, shoals, etc. are always moving or changing positions as Mother Nature reshapes the world. Charts are a good, a very good starting point but as with magazines, are often out of date by the time they get distributed. "Change is the only constant in the world."

As to your statement >>'Baiting' might be easy and fun, for some people. However, if it is directed at those who are at the early stages of learning the ropes of cruising; then the practice can be said to be of little value.<< The whole purpose of forums and debate is to educate newcomers to cruising about the realities and complexities of life "out there." Big brother governments and supposedly "updated" charts are not going to keep you and your crewmates alive or your ship intact when things change. The newbies had better learn that their knowledge and wits are what are going to keep them alive and enjoying the life on the seas. Everything else is merely supporting information to assist them in "commanding their vessel" in a safe and prudent manner. Relying on the 'oh my gosh, its so wonderful, sugar gooey discussions of this and that without "balancing" the negative realities of life on a cruising boat can at best ruin the enjoyment of the new cruiser and at worst cost them their boat, their lives, or their fortunes. I am "baiting" the fish hook to try to get some reality to the surface to be examined by one and all.

This is a good one, you said >>>Here is short list of where the geographic boundaries of coastlines and harbours were changed, resulting in major changes to nautical charts for those areas :- HERE << Since NOAA/NGIM and NGA both state in their disclaimers that they have not changed most geograhical or depth data in many years (except . . . ),. How is this link of any value to cruisers? It seems to me it falls right into the category of "misleading and patently false" information since any "updated" maps from these countries either do not exist or are not accessible by the ordinary cruiser.
__________________
osirissailing is offline   Reply With Quote
Old 08-15-2009, 10:18 PM   #47
Ensign
 
Join Date: Oct 2008
Posts: 27
Default

It take all kinds of people with all kinds of attitudes.

Reading through this topic illustrates this difference. Sailors with years of experience will be able estimate the amount of each writers experience by their attitude on this subject.

My introduction to the sextant was in 1960 in RCAF training. Since then flying maritime patrol over the Atlantic and flying with Canadian Pacific Airlines overseas using a periscopic sextant. I took a 3 star fix, worked it out, plotted the fix and recorded everything in the log every 30 minutes. Used a calculation sheet, HO 349 vol 3 and the Nautical Almanac. No computer, no calculator, just manually. Fixes off by more than 1.5 nm were suspect.

My wife, four children and myself sailed Vancouver, Australia, New Zealand and South Pacific Islands including the "Dangerous Archipelago" in safety for 5 years. We did this with only sextant, RDF, chronometer, Nautical Almanac, HO 349 and hand bearing compass. The children and my wife became reasonably competent with sextant, DR and general navigation. Not Impossible for people who was raised before 30 second sound bites.

Summary: A good navigator uses all his navigation aids to arrive at his best position in order to make safe decisions. A GPS is nothing more than an Aid to Navigation. It is not the navigator. Some people have the mistaken idea that the GPS is a navigator.

Remember, the brain, like the body, becomes stronger with exercise.
__________________
Gary

"I feel younger while afloat in my boat."

http//HealthyBoating.blogspot.com
Apolima is offline   Reply With Quote
Old 08-15-2009, 10:48 PM   #48
Rear Admiral
 
Join Date: May 2008
Posts: 332
Default

On a more basic front - nothing dispels your faith in technology more, when approaching a reef entrance and your GPS suddenly goes black followed by a bit of type running across the screen stating: 'signal lost'

Fortunately we also mark our position on paper charts and take bearings whenever we can as signal strength around New Cal seems to be a bit dodgy at times.

The signal seems to come back within a few minutes but I'd be feeling pretty vulnerable without the paper charts I can tell you.

Fair winds
__________________
mico is offline   Reply With Quote
Old 09-18-2009, 09:39 AM   #49
Ensign
 
Join Date: Jul 2009
Posts: 12
Default

Whilst it is true that many of the HOs do a lot of work keeping their charts up to date, it is also true that many also concentrate on the needs of commercial shipping and other commercial activities (as well as the needs of their navies). This is partly due to the high costs of carrying out accurate survey work to the standard of the IHO. Because of this, many areas visited by yachtsmen are not surveyed as often as one would like.

I'm actually involved in a research project related to this, and in Europe the UK says only 50% of its coastal waters (i.e. depth <200m) are adequately surveyed, and for other countries in Europe it may go down to 10% or less.

A lot of very good survey work is done, but financial constraints or restricted objectives of most HOs mean that more work could be done.
__________________
timtwickham is offline   Reply With Quote
Old 09-19-2009, 11:25 AM   #50
Admiral
 
Nausikaa's Avatar
 
Join Date: Sep 2005
Posts: 1,619
Default

Quote:
Because of this, many areas visited by yachtsmen are not surveyed as often as one would like
.

I say again, "all available information should be gathered using ALL available systems, the information examined and assessed for accuracy and errors and thereafter a careful analysis made to indicate the vessel's believed position.

The dangerous navigator is the one who knows exactly where he is. The good navigator is the one who from a believed position navigates with caution and care.

Navigation is not about criticizing one system whilst applauding another. It is a matter of common sense
."

The information provided by timtwickham is certainly interesting and underscores the need to exercise caution. There is nothing new about this though. Hydrographic offices do a great job but we have to recognise their limitations. But this is a little of a digression from the initial debate which was about the relative merits of different systems of navigation. What is worth mentioning in light of the prime issue here is that no matter what system of navigation we use from DR to plotters we are dependent upon the information from hydrographic offices either in paper chart or digital form.

Aye // Stephen
__________________
Yacht NAUSIKAA | Call Sign: 2AJH2




WHEN WAS THE LAST TIME YOU DID SOMETHING FOR THE FIRST TIME?

www.nausikaa.org.uk

= Sweden, Norway, Denmark, Lithuania
Nausikaa is offline   Reply With Quote
Old 09-23-2009, 03:40 PM   #51
Ensign
 
Join Date: Jul 2008
Posts: 1
Default

Quote:
ALL of the world's major oceanic airlines use GPS as primary navigation and the separation between individual aircraft is based on GPS. If GPS goes down, there will be a major crisis or many disasters in the airways of the world. GPS is even being used for "blind flying" or zero-zero visibility approaches and landing at major airports
Set your mind at ease. Aircraft use GPS as one of the sources of navigation information but no oceanic (or any other) aircraft relies soley on GPS for navigation. If GPS went 'down' no aircraft would crash and no aircraft would get lost. If GPS failed while an aircraft was on an approach, the systems would either have enough position information from other sources to continue the approach or the pilots would have to discontinue the approach and try another approach type. (Unless they could navigate visually).

There is no such thing as a GPS approach. Like any good navigator the aircraft uses all the information available to it, including GPS to keep it within set parameters. The approach is discontinued if the required information is not available.

There is no way an aircraft would be allowed into the air if all it took to crash was a GPS malfunction.
__________________

__________________
Kermit229 is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 06:50 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2016, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0