Whether such a device significantly mitigates risk depends on the diver and the dive. Military fighter pilots all have parachutes when they fly but passengers on commercial flights do not. Yes, I wear my seat belt when I drive, but the odds of me being in a traffic accident are much higher than my odds of being lost at sea; I won't be buying one. YMMV.How is it overkill and who said PAB/PLB's eliminate risk? Like the SMB you refer to, they are just more tools to assist in finding you when things "go south" - so they help to minimize risk, not eliminate it.