Plans for a $1.7 million a year scheme to improve marine safety in the Marlborough Sounds are being vigorously strongly opposed by commercial operators.
Submitters have told a hearing the plan won't stop boating accidents and the cost could force smaller operators out of business.
The Marlborough District Council has proposed a safety system which would involve fitting identification transmitters to all commercial vessels using the Sounds and building a centre in Picton to monitor the system.
Strait Shipping says the council is acting on an outdated risk report. It says ferries are already fitted with the system.
The organisation representing commercial fishermen and smaller operators says the scheme would be pointless without fitting the identification transponders to recreational vessels, which it says are the main cause of accidents and near misses.
The hearing is set down for four days.