In a harbour that was still largely under construction, a berth had been opened to shipping, while the contractor had surveyed the area and provided a locally produced chart for approaching vessels.
At the same time, a temporary buoyed channel had also been marked and tugs andpilotage were available.
Under calm conditions, daylight and good visibility, a laden, selfdischarging bulk carrier entered the channel to approach the berth.
For the reocrds, this was the third time the vessel had visited the new harbour.
The master and pilot had planned for an under-keel clearance of 1.5m, and two tugs were attached to assist.
During the final approach to the berth, the master observed that the water level in one of the ballast tanks had begun to rise and that a starboard list was developing.
In fact, a diver inspection after berthing identifed shell plating damage.
After the accident, the harbourmaster conducted an investigation, including an independent survey.
Accoding to the Safety Digest:
The investigation revealed that, in several areas of the harbour, the actual depth of water was signifcantly less than shown on the contractor’s locally produced chart, confrming that the vessel had grounded during its approach to the berth.
- Navigation in port areas where construction work is taking place needs to be undertaken with extreme caution.There will always be additional risk and uncertainty in such an environment.
- In this case, it was established that the contractor’s locally produced chart had been compiled using average rather than minimum depths.
- Charts showing average depth data are primarily for assessing the amount of spoil a dredging contractor has removed, and should not be used for navigation.
- If a locally produced chart is on ofer, it is vital to check that minimum depth data is shown before even considering whether to take it into account for passage planning.
- Masters and pilots should not hesitate to increase the under-keel clearance value to keep safe.
- Given the additional risks of operating in a harbour that was still under construction, it would have been sensible to plan for an increased under-keel clearance.