Fortunately no lives were lost when the 24 metre motor yacht Isamar struck the charted the Grand écueil d’Olmeto shoal but poor seamanship sank the rather pretty vessel. One suspects that each of the actions or inactions that led to the casualty seemed like a good idea at the time even if they conflicted with good advice at the time.
That the UK-registered vessel had its radar switched off might not have contributed to the loss but the fact that the echosounder – fathomometer for American readers – was switched on but had no shallow water alarm set might well have done.
It might not have mattered that the Electronic Chart System, ECS, had not been updated for 10 years, while indicating a certain laxity with regard to safe navigation, but the fact that it was used for primary navigation when paper charts are advised when using such a system, and set to a scale that did not reveal that there was a reef in the way, certainly did.
No waypoints or course marks were set on the ECS. After all, the captain had a pair of mark one eyeballs.
There are good reasons why an ECS is not recommended for primary navigation. In Isamar‘s case even at the scale which showed the shoal there were no depth indications.