boat towing over size

hi all looking at towing a boat in nsw that exceeds the 2.5m wide standard,my trailer will fully comply with oz specs but the boat that will sit on the trailer may be over size by about 50 to 100 ml either side does anyone out there know the permits required and signage required to be able to tow this boat to the letter of the law .I have looked on the rta web site but do struggle to understand it all now that there have been changes to the rules on towing over size loads.

kind regards Mick