You might find the hills out from Titirangi to Huia a bit much for the ute then , best you come out for a drive. The beach is easy to use three hours either side of high tide , the ramp is crap but you can on a low tide drive down the ramp and swing round on the rocks( small ,round ) to either side and launch that way , there are several 8.5m boats locally that use the beach and ramp.
On a really low tide you often have to drop the trailer off the end of the ramp , very rarely the bigger boats have to wait until there is an hours run of the tide before they can launch .
Flick me a pm if you come out for a drive ,I'll meet up with you and show you around . Rory