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.
It might have been prudent to carry paper charts, after all the UK Maritime and Coastguard Agency’s Marine Guidance Note (MGN) 379 (M+F) Navigation: Use of Electronic Navigation Aids advises: “If an ECS is carried on board, the continuous use of up-to-date paper
charts remains essential for safe navigation.” But someone decided paper charts were not required for Isamar. It was not best idea anyone ever had, the shoal was marked on the paper charts.
Says the UK MAIB: “Had appropriate, updated charts been available on board, Isamar‘s master could have prepared
a passage plan which would have enabled him to ensure that the intended route was suitable for Isamar’s draught.”
In the end, Isamar hit the shoal. Even then she might have been saved. However, says the MAIB report: “The standard marine emergency procedure of isolating damaged areas by closing watertight doors, were not applied, allowing the vessel to flood and sink faster than would have been the case had the watertight openings been closed. Flooding was not contained by closing the watertight door between the lazarette and the engine room, and pumping capability was not used to best effect. Had the watertight door been closed and the pumps set to pump out the engine room, the vessel would have stayed afloat longer and might have been saved.”
Rather than simply pointing at what went wrong it might be a good idea to ask why did the decisions that led to the casualty seem like such a good idea at the time.
Read the report here