It's an Auckland Council by-law at Wakatere that - 

ALL BEACH TRAILERS BE REMOVED FROM NARROW NECK BEACH WHEN NOT IN USE i.e. when you are out sailing. 

This is to provide full and safe use of the beach to the wider public.

Sailors, parents and supporters can all pitch in to help with this, even if it's not your own beach trailer, bring it up to the old road. 

Keep them clear of the cycleway.

Trailers, trolleys, it's all the same