A boat in Vanuatu, the LC Urata Riki, which sank on Sunday night, was carrying 3,000 cartons of 1.5 litre bottles of water destined for the islands to the south impacted by tropical cyclones Judy and Kevin at the end of February.
Chairman of the Water, Sanitation and Hygiene, or WASH, cluster, under the National Management Office Erickson Sami said the water was for the people on the southern islands of Aniwa, Erromango and Aneityum.
The ship was also carrying other relief supplies such as water tanks, which had been donated by the Australian government.
Sami said these items could not be recovered when the ship went down.
The company that operates the ship said there were no passengers aboard when the LC Urata Riki sank near Efate.
The crew, using the ship's dinghy, managed to get to Erakor island the following morning.
The WASH cluster, along with the management of the ship, are now trying to negotiate the replacement of the lost items.