Police say young revellers are heading into the Coromandel and their numbers are expected to build as the New Year draws closer.
Inspector John Kelly says there are already signs that problems last year with teenage drinking will be repeated this year.
There were 20 arrests overnight, most for breaching liquor bans. Most involved young people aged 17.
Inspector Kelly believes these teenagers are not being properly supervised, particularly with regard to their ability to obtain alcohol.
He says parents should know where their children are and set appropriate boundaries.