Water warriors who persistently ignore basic boating rules are putting lives at risk on the Whanganui River.
And Trevor Gibson, former Wanganui harbour master and education officer for Coastguard Wanganui said there had been instances recently where boats had ploughed through swimmers in the river.
"We've still got boats and jet skis towing 'biscuits' [inflatable rings] with no observer on board and acting in an irresponsible manner, and all of them going way faster than 5 knots."
He said users were simply ignoring the rule that says skippers must drop their boat speed to no more than 5 knots within 50m of another river user - whether it is another vessel, raft or person - or within 200m of the shore.
"All the river is governed by that 5-knot speed limit but nobody observes that," Mr Gibson said.
"It all hinges on Maritime NZ's rule 91, which pertains to navigation safety rules for recreational craft."
He said the problem had been around for some years now. But this summer there appeared to be more vessels using the river and a greater variety of them,  including boats and jetskis.
Mr Gibson said there was a growing mix of river users, including rowers, waka crews and kayakers, along with jetskiers and boats towing waterskiers.
He said the speed limit was being ignored all the way up the river from the bar at Castlecliff to Raorikia, just downstream from Hipango Park.
"We're getting reports all the time about speeding. They think it's a hell of a joke," Mr Gibson said.
"We had a report recently of swimmers at Mosquito Point heading for the other side of the river and this bloke towing a biscuit behind his boat just going right through them.
"That's just an accident waiting to happen."
There was another incident involving a boat steaming through a rowing regatta at speed.
But Mr Gibson said there was not a lot the authorities could do.
"It's often comes down to identifying the vessel involved and the bylaw Horizons is working on currently will include that as part of the regulation."
He said the bylaw was in draft form  and it would be a few more months before it was in place.
"It's courtesy when you're passing another vessel to slow down and there are some good boaties who do that. But there's more bad ones than good ones.
"If some of these people drive on our roads the way they do on the river, we're in trouble,"  Mr Gibson said.
Pat Spriggens, long-time club captain at Aramoho-Wanganui Rowing Club,  supported any effort to keep speeds down on the river but said it was really a matter of being able to identify the boats.
WATER WAYS