Reef Explorer II (REX II) is an underwater vehicle that provides live video and sensor data to a remote operator. It incorporates the mobility of traditional AUV designs with the live control and feedback of ROVs. An automatically managed tether connects the vehicle to a small surface float with radio communication and GPS. This design, inherited from the preceding “Reef Explorer”, creates a fast data connection between the vehicle and operator, and gives accurate navigation information. The operator can be near the vehicle, or connect over the Internet. In spring of 2009, Rex II was sent to Oahu, Hawaii for ocean field tests. It captured many hours of video and images over several missions conducted at reefs, sandbars, harbors, and deep channels. Many different forms of sea life, such as fish, turtles, invertebrates, plants, and corals were recorded.