Never drop in on another surfer uninvited, it’s against the law. Kinda.
Carve Magazine concisely explain the drop in law and potential consequences, as follows:
“One drop in is an accident, two is rude, three is a twatable offence.”
If you do accidentally drop in; exit at the earliest opportunity and apologise to the surfer you’ve violated.
If you think the drop in law does not apply to you, be prepared for the penalty.
Here’s a surfing Crime and Punishment gallery as evidence:
Surfer Dad in no way condones aggressive behaviour, even if someone does drop in on you. In the words of Julie-Ann Burkhart “I like to encourage aloha and also know I was once a beginner. Spread good vibes!”.