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WHY MUST WE UPDATE CHARTS?

  • Whilst land does not move too readily, changing sandbanks,  sunken craft, changing light signals, and new buoyage make the whole process so much more important. To find flashing lights from a buoy or lighthouse ahead of you when there is no mention of it on your chart is rather disconcerting at night. This is certainly the time to wake the skipper to help resolve the problem. So whilst it is still winter and we are arm chair sailing this is a good time to get the charts out and make those corrections.

  • Over the course of time chart corrections are published in Notices to Mariners These are readily available to download from the internet or you may find them in various Boating and Yachting Magazines. Locally on Admiralty Chart 1152 there have been some very recent buoyage changes. In addition Local Notices to Mariners are available from Sedgemoor District Council Site

  • It is easy to overlook this procedure but this need not be so daunting as you might first think

WHAT DO YOU NEED?
The essentials are a pen with a very fine point (preferably magenta in colour so that it shows up clearly), a copy of Chart 5011 - Symbols and Abbreviations used on Admiralty Charts and internet access to www.admiraltyleisure.co.uk and the free of charge Admiralty Leisure Notices to Mariners website.

  • STEP 1 Look at the bottom left hand corner of your chart and find the edition date. This is Chart 1152 Bristol Channel Nash Point to Sands Point. You will also see the Year and identity of corrections applied to this chart.

  • STEP 3 Applying the Notice to Mariners
    This is best done with indelible ink as ordinary ink may smudge on damp charts.

  • Determine if the Notice is applicable to your chart and your vessel. You may decide that it isn’t relevant to your vessel. For example, changes to a very deep sounding or a new cable in very deep water are not necessarily of interest to the leisure mariner.

  • Apply The Correction. When replacing a symbol, find the symbol to be replaced on the chart. Then, as close as possible and not over any other information, draw the new symbol.

  •  (check Chart5011- SYMBOLS AND ABBREVIATIONS USED ON ADMIRALTY CHARTS ). Link the new symbol to the required position with a curved line. Finally draw two diagonal lines through the old symbol to show that it no longer applies. Always insert new information before you delete any information.

  • When inserting a new symbol, place it on the exact position given in the NM. If there isn’t room follow the process above for a ‘replacement symbol' (see below)

  • You can find detailed instructions and examples of how to apply corrections to charts in the UKHO’s publication NP294 - How to Correct your Charts the Admiralty Way.

  • Document The Corrections Applied. Check your work and then, in the bottom left-hand corner of the chart, make a note of the number and year of the NM. Only do this once you have applied the correction and not before

  • If you decide that a correction does not apply to your vessel, making a note of the correction number on the chart will save re-checking at a later date.

  • On occasions coloured blocks are published by the Hydrographic Office. These may be printed and affixed to your chart, however care should be taken that the printer scales the block correctly to match your chart scale. You may need to calibrate the printer.

  •  STEP 4. Now all that work is done plan your next trip afloat with confidence knowing that your charts are all up to date.

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