''Next thing, the front of the dinghy lifted up and it came across my helmet, hit me on the head and knocked me off my bike,'' Mr McDiarmid said.
The under-18 Northland hockey team's star goalie has a strained neck and a torn bicep, meaning he's likely to miss a season of the sport he loves to bebe laid up off work for at least seven weeks.
''All for something as stupid as a dinghy flying off a ute and hitting me because it wasn't tied on properly.''
Yesterday afternoon, 24 hours after his accident, Mr McDiarmid was still shaken and sore, but not in the state of shock he had been.
Doctors at Whangarei Hospital, where he was rushed after the incident, unable to move his neck, told him he was ''very lucky''.
Mr McDiarmid spent one night in hospital after having x-rays and a CT scan.
He is surprised the driver of the ute did not stop to help, although he dropped his passengers off.
''They said they didn't know him. One of them said he'd been at the wharf and helped the driver put his dinghy on the ute, then the guy offered him a lift to town.
The woman said she'd been hitchhiking and the driver had stopped for her at the top of the [Onerahi] hill.''
Mr McDiarmid said one aspect of his building work that his boss always stressed was the need to secure a load properly.
''It's a warning, you should know what you're tying down and how to do it.''
He said he was angry about the accident that has left him with at least one injury which could yet require surgery, his bicep muscle. It also smashed his uninsured scooter.
He hoped the driver of the vehicle would own up to his actions.
Mr McDiarmid said he had not been visited by police but he knew they had the crash details.
Whangarei Sergeant Rachel Wood confirmed the police had the dinghy and would like'' to have a chat'' to the driver of the older style, dark coloured ute.
He is invited to contact Sergeant Wood at the Whangarei Police Station on 09 430 4500.