"None of them were wearing life jackets, but once the boat started sinking they had time to get three of the jackets and give them to those most in need of them,'' Mr Paget told NZPA.
"The missing man was one of those who was given a life jacket, but we now know that he didn't put it on properly. There was a waist strap which should have been done up that wasn't.
"Eventually he became separated from that life jacket.''
The group tried to swim about 2km to Motuketekete Island, near Kawau Island, splitting into a group of three and a group of two, which Mr Preston was in.
Sometime during the night Mr Preston became separated and it was highly unlikely he survived.
Mr Paget said there were three lessons boaties could learn from the incident.
"Firstly, you need to be sure somebody ashore knows your plan and what time you will be returning. Nobody knew how long this group was going out for.
"Secondly, you need to have life jackets immediately available if something happens, and preferably worn before anything can happen.
"Thirdly, you need to be sure any communication devices that you intend to use in these circumstances needs to be able to work once you are in water.''
Flares and water-tested communications equipment would have helped in this case, Mr Paget said.
"A lot of people have radios and mobile phones but unless they are going to work when they are in water they are not much use.
"There is equipment specifically designed for use in these conditions which people should have.''
The search for Mr Preston will resume tomorrow when Mr Paget said a decision would be made on whether to bring in underwater cameras.
- NZPA
