New Zealand Navy divers in Tonga are hoping they can avoid further problems in their efforts to confirm the site where the Princess Ashika has settled after sinking.
149-people are believed to have been aboard when the ferry sank twelve days ago and 93-people are still missing.
Navy sonar equipment found what is thought to be the wreck last week in 110-metres of water.
Lieutenant Commander Andrew McMillan says detailed sonar has been able to pick up debris like ropes in the area and these can cause problems for search vessels.
