I have always wondered what I should do if I was out and saw a reasonable size shark.

Scenario 1: I am paddling back to shore at big left (1 km paddle from the break) and see a shark. No amount of yelling or arm waving would get the attention of surfers. I would like to think I would paddle back out and tell them. Would you?

Scenario 2: I am surfing by myself, a shark comes up close so I go in. There is no one to tell but it is inevitable that others will come for a paddle. Do you sit on the beach to warn people? Do you make a sign? Do you call 000?

Is there an app for that?