Bird watchers who

Members of a nature photography group who survived a freak boat capsizing near Kaiko¯ ura, possibly caused by a collision with a whale, are in ‘‘deep grieving’’ over the tragedy that claimed five lives.

‘‘They’re shocked, they’re saddened and wanting to get back home,’’ said Nature Photography Society of New Zealand spokesperson James Thompson of the Saturday disaster at Goose Bay, south of Kaiko¯ ura.

The people on board were a group of society members who had planned a three-hour bird-watching trip with Fish Kaiko¯ ura, a local fishing charter business whose skipper had more than a decade’s experience.

The boat called mayday at 10am, sparking an hours-long search and rescue operation for survivors.

Eleven were on board the 8-metre boat, including the skipper. The boat was allowed to carry 10 passengers and at least one crew member.

The bodies of the five who died are understood to have been recovered from inside the cabin. Some of the six who were rescued nursed injuries.

Thompson, who was not on board after a change in plans, said he had spoken to some survivors.

‘‘They’re going through a deep grieving process and that process of letting it sink in . . . there’s minor injuries, there’s one person who is still receiving hospital treatment, but the rest have all been [discharged].’’

The whale collision was the ‘‘initial report that came through the grapevine,’’ he said.

‘‘None of the people who were actually on the boat have said to me personally, that that’s what actually happened, [but] it does seem like that is a possibility and obviously Maritime New Zealand and police will follow up.’’

Thompson did not know if the boat was stationary at the time of the incident, nor if those on board wore life jackets.

He said the boat trip was only part of the weekend trip away.

‘‘Obviously it’s shock to the society’s members, a lot are still trying to work out and come to terms with the fact that it’s happened.’’

‘‘Our thoughts and prayers go out to family members and friends of the members who didn’t survive.’’

The society members who had not yet gone home would do so yesterday, he said.

The society also issued a statement to its Facebook page saying it was ‘‘saddened by the tragic loss at sea in Kaiko¯ura during a trip by society members that took the lives of 5 of our members’’.

Investigators from Maritime NZ travelled on Saturday from Christchurch to Kaiko¯ura to begin their inquiry into the disaster, following the recovery of the bodies, and the boat, on Saturday evening.

Maritime NZ principal investigator Tracy Phillips said it would begin a ‘‘thorough’’ investigation under the Health and Safety at Work Act and the Maritime Transport Act, and would support police in their investigation.

Yesterday, a Maritime NZ spokesperson said the inquiry would involve review the conditions on the day, examining the vessel and interviewing the people involved.

‘‘We will conduct our investigation with the utmost sensitivity for those involved,’’ the person said.

‘‘The exact circumstances surrounding the incident are still to be established.’’