For most field trials and autonomy testing, our group in the Laboratory for AutonomousMarine Sensing Systems at the Massachusetts Institute of Technology uses two Bluefin 21” AUVs (21” hull diameter, ∼3 m in length). To maintain reasonable stability control and navigational accuracy, the AUVs are usually commanded to travel at 1.5 m/s (though this speed varies due to autonomous adaptation to the AUVs’ situations) and surface for a GPS position fix every 30 minutes, resulting in about 50-100 m of navigational error. Other instrumentation currently on board consists of a conductivity-temperature (CT) sensor, a pressure sensor, and an acoustic modem with transducer, however, these vehicles could also be equipped with sensors that could measure chemical tracer concentrations or biological (Chlorophylla, Colored Dissolved Organic Matter, etc.) concentrations for the purposes of detecting oil, hydrothermal vent fluid, or algal concentrations. For communicating with the AUVs, we make extensive (and nearly exclusive) use of an acoustic communication structure (AUV-to-AUV and AUV-to-ship/lab) that has been actively developed and refined in recent years to give virtually real-time updates (delays on the order of minutes) of scientific and navigational data. Linking all of these pieces together is the autonomy system on board each AUV. This includes the Mission Oriented Operating Suite (MOOS) and the IvHelm (IvP stands for Interval Programming), which coordinate to implement the execution of autonomy behaviors by the AUVs. These behaviors autonomously and adaptively control the heading speed and depth of the vehicle, depending on the behavior the AUV operators have chosen to run.