Madam, – Ordnance Survey Ireland and Ordnance Survey Northern Ireland are jointly scrapping the 1:50,000 “Discovery” series Irish National Grid in favour of another system called the Irish Transverse Mercator. Countless guidebooks and navigational aids face unplanned obsolescence. That the changeover will take more than two-and-a-half years to roll out will hugely frustrate anyone, such as guide writers, forced to deal with the problems.
It should be a time of opportunity too. Is it too much to hope that OSI/OSNI, when they are in “change” mode, might address the biggest weakness in the whole system, namely that shallow seawater depths are not given?
The current Discovery sheets only show High Tide and Low Tide. That means all you get is dry land, deep water and the bit in between. The old half-inch series gave all that and showed the five and 10 fathom contours.
This extremely useful additional information has been available since the mid-19th century and was shown on OS maps for all coastal areas for generations, but was abandoned about 20 years ago when the Discovery series came out. That was a pointless mistake which OSI now have the opportunity to put right.
Sea charts are all right for professional seamen, but the tens of thousands who mess about in small boats for recreational purposes use OS maps.
OSI maps are created from photographs taken by aircraft, which by definition can’t see under the sea. OSI used to claim they couldn’t manually over-ride their modern computer aided maps with such information. That is manifest nonsense. They manually insert all sorts of other information. They should loudly receive the message: Yes you can. – Yours, etc,