The incident in question took place in July 2006, when five people on board an Emerald Star cruiser ran aground at Urra Point on Lough Derg.
Emerald Star towed the boat to safety, but did not inspect the hull of the boat before allowing the customers to proceed back out onto the lake.
The hull, later inspection revealed, had a metre-long tear in the fibreglass alogn its skeg, and soon began to let in water. Although no-one was hurt in the incident, local search and rescue teams were called to assist the stricken holidaymakers, who had raised the alarm by phone, as there was no VHF radio on board the boat.
The MCIB found that Emerald Star had failed to fully safeguard their clients by not carrying out a full inspection after the vessel ran agound.
The MCIB also found that the bouyage system on Lough Derg may have contributed to the incident, as it differs from that used elsewhere on Irish inland waterways and may be confusing for water users. It recommended to Waterways Ireland that it should bring its bouyage into line with international standards.