Given the widespread acceptance of the Automatic Identification System in the past several years, it’s little surprise that many sailors now carry an AIS-enabled man-overboard device, also referred to as a personal AIS search-and-rescue transponder (SART), instead of a personal locator beacon as their preferred safety equipment. Rather than transmitting satellite messages, as a PLB does (more on this in a minute), AIS devices notify local marine traffic (within VHF range) about an emergency situation using dedicated VHF channels. When activated, an AIS MOB device such as McMurdo’s Smartfind S20, Marine Rescue Technologies’ sMRT AU10 or WamBlee’s W420 transmits its AIS reports, complete with GPS information, once per minute. The range of these devices increases if that transmission coincides with cresting waves, thus increasing the line-of-sight VHF range. While these devices aren’t registered to individual users, they are designed to enable rescue via local vessels monitoring AIS traffic.