Use a flag on a simple float with bright yellow braided poly line tied to it. Thus far no dives over 20' with it, and luckily have had no PWC morons attempt to play tag-the-flag with it.
I have debated having a watch on the beach armed with a .30-06 and VHF on ch16 to let the CG know that the smoking boat tried to kill divers.. especially after wathing a boat race right up between 2 flags off shore under which were 3 scubaboarders, one being my wife.
I have debated having a watch on the beach armed with a .30-06 and VHF on ch16 to let the CG know that the smoking boat tried to kill divers.. especially after wathing a boat race right up between 2 flags off shore under which were 3 scubaboarders, one being my wife.