Database of uncharted or wrong charted reefs and hazards?

[Franziska]

Hi,

just read another thread about a yacht which seems to have ended up on a wrongly charted reef.

I was wondering if it's an idea to create a database of such hazards which some are aware of, but the charts do not show correctly.

Would it make sense to integrate that in Ocpn?
Or just as a collective thread on Cruisers Forum?

Any thoughts,

Franziska

Welcome to the Woods Mira 35 - Catamaran Lady Rovers Website!

[CarCode]

Franziska,

you cannot be safed by a computer or by a software. You must use your eyes or other senses e.g. for safe navigation. Also some experience might be useful when you navigate.

Gerhard

[Franziska]

Well I agree that a computer is second only, BUT the knowledge of the crowd can help awareness.
Especially when planning a trip.

I am talking of information which is NOT readily available without local knowledge.

Some charts in the Med are for example way old.
If you rely on something and do not notice it is wrong (which can really happen to EVERYONE) you may end up in a place where you do not want to be.

Crowdsourced info can augment other sources (eyes,ears, charts,guidebooks....)


www.ladyrover.jimdo.com

[44'cruisingcat]

Sounds like a good idea.


Verification may be a problem though.

Something we were lucky enough to be able to access when venturing into poorly charted areas of the coral sea, was tracks from people who had been there before us.

Being extreme shoal draught doesn't hurt either.

[bcn]

What about using sQuiddio for this purpose?

[barnakiel]

There is such a list for Tonga, e.g.

But since they are uncharted, what good use is if we know they are out there without actually knowing where?

If we go for such a list, I think we could go by areas and make some kind of an edit audit - like say a wikipedia style.

How about the Cruising Wikipedia, maybe there? Does it allow for digital signing and backtracking of the edits?

BTW Sailors hitting uncharted reefs is often just the word for lame watch keeping and ignorant navigators (remember Vestas?)

b.

[barnakiel]

Originally Posted by Franziska

(...)

I am talking of information which is NOT readily available without local knowledge.

(...)

Avoid local knowledge. It is often inaccurate: locals sail by heart, they will tell you there is a rock but not tell you exactly where. To navigate, you WANT the position and the more accurate it is, the better.

You are better off with info gathered from other cruisers - those who had a close shave and those who had no such luck.

Back to your project, I think the dangers could get admiralty style 'grades' - to quickly and clearly tell the quality of information on which we based our entry into the dangers list.

BTW - how do we make an accurate gps fix of a danger, without landing / crashing on it?

b.

[DumnMad]

Originally Posted by Franziska

Hi,

just read another thread about a yacht which seems to have ended up on a wrongly charted reef.

Welcome to the Woods Mira 35 - Catamaran Lady Rovers Website!

Wrongly charted is very different from uncharted and I think Fran is referring to a thread which comments about a wrongly charted harbour entrance channel.

Seems it would be a great idea to have a list of wrongly charted entrance channels. Might encourage some countries to correct the charts.

[Franziska]

Correct. I do mean wrongly charted.
I am not after local knowledge like shortcuts or the like.
Just anything which is clearly wrong and might lead to desaster.

www.ladyrover.jimdo.com

[NAV]

One would expect that such discoveries are reported by mariners and sailors to the hydrographic office of the country responsible for the chart production in that particular area.

[Dsanduril]

I have often thought that a crowd-sourced track/depth repository would be useful. Weeding out the bad data is a task, but there is likely to be very little governmental survey of out-of-the-way places we like to cruise, so it likely falls to us to see if we can generate new data.

Having said that, I have had a number of interactions with both NOAA and the British Admiralty about charting errors, and both are more than happy to receive submissions. Particularly when they relate to channels and channel markers. A GPS track, depth profile, and photos go a long way to providing all the information needed to at least get a note added to the chart.

For those two biggies, you can report online here:

NOAA's Nautical Discrepancy Reporting System

and here:

Hydrographic Notes

[NAV]

And to contact the Dutch Hydrographic Office: see BaZ1 (NtM1) of each year, chapters 2 (reporting of errors in charts and documents) and 6 (reporting of shallower depths observed by echosounding).

BaZ1 of 2016 can be found here: https://www.defensie.nl/documenten/p...015/12/17/baz1