How often do you update your charts

[awol]

In a fit of anticipation I reviewed my chart table drawer earlier this year and topped it up with the Admiralty Leisure Folio of the West Coast, after first asking if a new issue was expected. Now one of the problems with these folios is that they don't come with corrections incorporated so I then spent a couple of evenings incorporating the NMs and cursing HMS Gleaner and her survey of Coll.
I looked at the UKHO site this evening for more NMs on my proper charts and also looked for the West Coast folio only to find that Issue 2 dated early March has superceded mine and, of course, the previous NMs have disappeared including any I may not have caught, and I haven't even used the things yet!

So as a matter of interest:

 

[shmoo]

Deben Bar - several times in the season
Channel Islands - less often

SeaClear electronic charting package lets you rescan your updated charts after youve corrected including with the nice stick-on bits you can download from UKHO NMs. So electronic doesn't always mean never.

 

[Searush]

I used to do it every year, but I found I was just correcting corrections one after another! I wish there were 2 levels of corrections - say critical long-term ones & temporary/ pedantic ones!

Now I just never trust the chart. Like cruising/pilot books, it is a useful GUIDE & no more. What I see & what my instruments measure, is what I got!

 

[AndrewB]

"Sea monsters", ho-ho!

Two months ago I was cruising around Grenada using an Admiralty chart dated 1928. No sea-monsters but in one corner it has a nice engraving of a square-rigger approaching the island under full sail. The chart shows the original survey information and is actually far more detailed than the modern equivalent. I even used it for hiking ashore as it shows the location of the old mule-trails - where they are not buried under modern development.

 

[Robin]

One advantage of Imray charts is that you can download chart specific updates much easier than Admiralty ones. I print these off and file them with the chart, I don't alter the chart except for those changes which are important for where I go and which are relevant to a saily boat as opposed to a supertanker. So many of the NMs refer to new fish farms I'm not going to get remotely close to or are changes of depths way above any depth we need and so on. Changes to lights are recorded if the characteristics change (colour, type of flash, times etc) but not for changes in luminous range, we do carry latest almanacs with Lights Lists incorporated for all of our regular sailing areas (French Votre Livre De Bord).

Our electronic charts are rarely updated except where a really major change (like Ushant TSS repositioning a year or so back) but buoy changes/moves that are on our regular routes are modified by me on our C-Maps via the plotters inbuilt 'mark' symbols, an 'x' through a removed buoy for example and new ones inserted as port/stbd symbols.

I used to be a lot more diligent but then realised that many if not most changes which I was personally aware of didn't get into NMs for several months and quite a few of these had been changed again (but not yet in NMs) before the 1st NM was published.

I should stress that we sail in deep water areas amongst rocks and not shallow waters full of shifting sands and mudbanks. If we were East coast based I might think entirely differently.

 

[Boathook]

Old charts with a new almanac. The land does not move so even an old chart is accurate to 100 yards. And when you look at the survey dates for some areas, the old charts are still in date. Someone else mentioned instruments being helpful plus I would add the eyeball mk 1 to the list until the fog clamps in at 200 yards ...

 

[shmoo]

There is a sentiment running through some of the posts here which reminds me of an old Swedish Army saying (before you knock it - the connection is that they invented orienteering)

"if the terrain differs from the map, believe the terrain"

 

[Richard10002]

In 2004, approaching Finisterre traffic lanes from the NW and, intending to head inshore once we had passed the southern end of the lanes, we wondered why ships were heading North, straight for us.

Seems that the lanes had been moved West a few years previously, so aiming for south of the bottom of the old lanes, put us right in the middle of the new lanes, (as was confirmed by Reeds Almanac, (or whatever it's called these days).

Turned left to cross at 90 degrees.

Bought new charts and cartridges last year, and will be probably buying new again for the next leg of our adventure, but dont expect I'll update much, but will always check the almanac.

 

[Mudplugger]

As Robin implied, if you sail on the East Coast, the land moves!... at least the banks do!, unlike you lot down souf where the rocky bits tend to stay in the same position....so one does tend to be a little more careful!