The listing of US-based Aquabotix makes it one of the few pure-play publicly-listed underwater drone companies. The company makes portable underwater vehicles, which it says are used by commercial, educational, industrial, government, military and recreational applications and by anyone looking to explore under water. According to company filings, since 2011, Aquabotix has sold 840 units in over 45 countries and has customers such as Australia’s Broadspectrum, various US defense forces and government departments, BP, Shell and ConEdison.