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Many pelagic animals, such as krill, lanternfish, and cephalopods, migrate to deep water at dawn to avoid visual predators during daylight hours and move up toward the sea surface at dusk to search for food. This behavior is termed “diel vertical migration.” Migrating animals graze on phytoplankton or zooplankton and in turn serve as food for higher trophic levels, hence providing a key mechanism for carbon export via this migration. These animals are often observed as sound-scattering layers by echosounders, but the animals causing the acoustic scattering are difficult to identify using acoustics alone. In a spring 2019 experiment in Monterey Bay, we deployed autonomous underwater and surface vehicles over a seabed-mounted upward-looking echosounder to collect environmental DNA (eDNA) with the goal of identifying the vertically migrating animals. The echosounder was installed at 890-m depth on the Monterey Accelerated Research System (MARS) seabed cabled ocean observatory, providing real-time data of acoustic backscatter from the full water column. One long-range autonomous underwater vehicle (LRAUV) carrying a Third-Generation Environmental Sample Processor (3G-ESP) acquired water samples from a sequence of layers from near surface down to $\sim$ 290 m as directed by the distribution of animals observed by the echosounder. During the sampling of each layer, the LRAUV ran on a tight circular yo-yo trajectory directly above the echosounder, remaining in its beam by acoustically tracking a station-keeping Wave Glider on the sea surface marking the echosounder's latitude and longitude. The persistent and simultaneous acoustic observation and eDNA acquisition enables identification of animals at precise locations to better understand their vertical migration behaviors. We present the methods and the system performance in the experiment.

Phytoplankton communities residing in the open ocean, the largest habitat on Earth, play a key role in global primary production. Through their influence on nutrient supply to the euphotic zone, open-ocean eddies impact the magnitude of primary production and its spatial and temporal distributions. It is important to gain a deeper understanding of the microbial ecology of marine ecosystems under the influence of eddy physics with the aid of advanced technologies. In March and April 2018, we deployed autonomous underwater and surface vehicles in a cyclonic eddy in the North Pacific Subtropical Gyre to investigate the variability of the microbial community in the deep chlorophyll maximum (DCM) layer. One long-range autonomous underwater vehicle (LRAUV) carrying a third-generation Environmental Sample Processor (3G-ESP) autonomously tracked and sampled the DCM layer for four days without surfacing. The sampling LRAUV's vertical position in the DCM layer was maintained by locking onto the isotherm corresponding to the chlorophyll peak. The vehicle ran on tight circles while drifting with the eddy current. This mode of operation enabled a quasi-Lagrangian time series focused on sampling the temporal variation of the DCM population. A companion LRAUV surveyed a cylindrical volume around the sampling LRAUV to monitor spatial and temporal variation in contextual water column properties. The simultaneous sampling and mapping enabled observation of DCM microbial community in its natural frame of reference.

Accurate methods to track changes in lake productivity through time and space are critical to fisheries management. Chlorophyll a is the most widely studied proxy for ecosystem primary production and has been the topic of many studies. The main sources of chlorophyll a measurements are ship-based measures or multi-spectral satellite data. Autonomous underwater vehicles can survey large spatial extents approaching the scale of satellite data, but with the accuracy of ship-based water sampling methods. We use several statistical measures to compare measures of chlorophyll a collected in Lake Michigan with spatiotemporally matched satellite-derived measures of chlorophyll a from the MODIS Aqua multi-spectral sensor using NASA's OC3 and the Great Lakes Fit algorithms. Our findings show a near one to one relationship between AUV data and both satellite-derived data sets when the AUV data are coarsened to the resolution of the satellite data. A comparison of satellite-based chlorophyll a to AUV-derived chlorophyll summarized in discrete water depth bins suggested that, based on decreasing coefficients of determination, satellite estimates of chlorophyll accounted for the most variability in chlorophyll a concentrations in the upper 10 m of the water column, even though satellite sensors may detect past this depth.

Mesobot, an autonomous underwater vehicle, addresses specific unmet needs for observing and sampling a variety of phenomena in the ocean's midwaters. The midwater hosts a vast biomass, has a role in regulating climate, and may soon be exploited commercially, yet our scientific understanding of it is incomplete. Mesobot has the ability to survey and track slow-moving animals and to correlate the animals' movements with critical environmental measurements. Mesobot will complement existing oceanographic assets such as towed, remotely operated, and autonomous vehicles; shipboard acoustic sensors; and net tows. Its potential to perform behavioral studies unobtrusively over long periods with substantial autonomy provides a capability that is not presently available to midwater researchers. The 250-kilogram marine robot can be teleoperated through a lightweight fiber optic tether and can also operate untethered with full autonomy while minimizing environmental disturbance. We present recent results illustrating the vehicle's ability to automatically track free-swimming hydromedusae (Solmissus sp.) and larvaceans (Bathochordaeus stygius) at depths of 200 meters in Monterey Bay, USA. In addition to these tracking missions, the vehicle can execute preprogrammed missions collecting image and sensor data while also carrying substantial auxiliary payloads such as cameras, sonars, and samplers.

Studies of marine physical, chemical, and microbiological processes benefit from observing in a Lagrangian frame of reference. Some of these processes are related to specific density or temperature ranges. We have developed a method for a Tethys-class long-range autonomous underwater vehicle (LRAUV) (which has a propeller and a buoyancy engine) to track a targeted isothermal layer (within a narrow temperature range) in a stratified water column when operating in buoyancy-controlled drift mode. In this mode, the vehicle shuts off its propeller and autonomously detects the isotherm and stays with it by actively controlling the vehicle's buoyancy. The LRAUV starts on an initial descent to search for the target temperature. Once the temperature falls in the target center bracket, the vehicle records the corresponding depth and adjusts buoyancy to hold that depth. As long as the temperature stays within a tolerance range, the vehicle continues to hold that depth. If the temperature falls out of the tolerance range, the vehicle will increase or decrease buoyancy to reacquire the target temperature and track it. In a June 2015 experiment in Monterey Bay, CA, USA, an LRAUV ran the presented algorithm to successfully track a target isotherm for 13 h. Over the isotherm tracking duration, the LRAUV mostly remained in the 0.5 $^\circ $ C (peak-to-peak) tolerance range as designed, even though the water column's stratification kept changing. This work paves the way to coupling an LRAUV's complimentary modes of flight and drift—searching for an oceanographic feature in flight mode, and then switching to drift mode to track the feature in a Lagrangian frame of reference.

Environmental DNA (eDNA) can be used to identify macroorganisms and describe biodiversity, and thus has promise to supplement biological monitoring in marine ecosystems. Despite this promise, scaling sample acquisition to the spatial and temporal scales needed for effective monitoring would require prohibitively large investments in time and human resources. To address this challenge, we evaluated the efficacy of an autonomous eDNA sampling system and compare results obtained to traditional eDNA sampling methods. The autonomous sampling instrument consisted of the Environmental Sample Processor (ESP) coupled to an autonomous underwater vehicle (AUV). We tested equivalency between the ESP and traditional eDNA sampling techniques by comparing the quantification of eDNA across a broad range of taxa, from microbes (SAR11), phytoplankton (Pseudo-nitzschia spp.), and invertebrates (krill: Euphausia pacifica) to vertebrates (anchovy: Engraulis mordax). No significant differences in eDNA densities were observed between the two sample collection and filtration methods. eDNA filters collected by the ESP were preserved and stable for 21 days, the typical deployment length of the instrumentation. Finally, we demonstrated the unique capabilities of an autonomous, mobile ESP during a deployment near Monterey Bay, CA, by remotely and repeatedly sampling a water mass over 12 h. The development of a mobile ESP demonstrates the promise of utilizing eDNA measurements to observe complex biological processes in the ocean absent a human presence.

The use of autonomous vehicles (AUVs) can greatly increase the efficiency of science campaigns, reduce human impact and effort, and provide a more tractable expansion of ocean observing systems. This paper highlights a variety of autonomous vehicles and their contributions to specific science applications. We also explore ongoing development projects and the role autonomous systems will play in the future. Over the past decade, the operational domain of autonomous vehicles has expanded to higher complexity tasks with less power required to achieve them. Hundreds of autonomous vehicles are now available to the science community, and their growing ability to carry highly specific and complex payloads for longer durations is transforming how ocean scientists do research. This paper focuses on two broad areas where autonomous vehicles have provided significant value: time-series observations and ocean feature detection and observation.

One of the greatest challenges to understanding ecosystem dynamics in the open ocean is predicting where and when hot spots of biological activity exist and then observing and sampling those features for days to weeks, as they move in a complicated trajectory. It is difficult to apply traditional research vessel-based techniques at the relevant temporal and spatial scales when the biological features could be spinning in an eddy, rising and falling on internal waves, or even actively migrating. To address this challenge the Monterey Bay Aquarium Research Institute (MBARI) is developing an observing system based on a collaborating group of autonomous underwater vehicles (AUVs) and an Unmanned Surface Vehicle (USV). Building on the capabilities of the Long Range AUV (LRAUV) and a Liquid Robotics SV-3 Wave Glider, MBARI has begun deploying arrays of LRAUVs configured with complementary sensors that work together as an Open Ocean, Autonomous Vehicle-based Lagrangian Observatory.

Mesobot, a new class of autonomous underwater vehicle, will address specific unmet needs for observing slow-moving targets in the midwater ocean. Mesobot will track targets such as zooplankton, fish, and descending particle aggregates using a control system based on stereo cameras and a combination of thrusters and a variable buoyancy system. The vehicle will also be able to collect biogeochemical and environmental DNA (eDNA) samples using a pumped filter sampler.

In 2017 a team from MBARI and Stanford University deployed an AUV in Sermilik Fjord in Greenland to map the walls of icebergs. 24 missions were run over a period of a week, and a detailed 3D map of a specific iceberg was obtained. This paper describes the design of the control and obstacle-avoidance system and subsequent field operations.

The overarching logistical challenge in microbial oceanography is acquiring enough samples to provide meaningful scientific interpretation. The number of samples collected during ship expeditions is limited by weather, time on station, and budget. Here we describe a robotic, autonomous vehicle platform equipped with a unique sampling instrument that mitigates some of these constraints. In a joint cruise on the R/V Falkor, the Monterey Bay Aquarium Research Institute and the University of Hawaii deployed two of these vehicles in a mesoscale eddy north of the island of Maui. One vehicle collected contextual measurements while circling a freely drifting sampling vehicle. On the sampling vehicle we implemented several behaviors, including sampling every three hours for a 4-day underwater drift while maintaining position within the deep chlorophyll maximum layer (~100m). Results demonstrate the ability to remain with features of interest and point to an exciting future of long-term, directed, persistent sampling.

The recent proliferation of icebergs in the Southern Ocean and the chemical and biological enrichment recently identified in the surrounding water raise the question of whether these icebergs are major contributors to drawdown of CO2 and the export of organic carbon to the deep ocean. The Lagrangian sediment trap (LST) was developed to measure the carbon export associated with these free-drifting icebergs. The core of the LST is a neutrally buoyant Sounding Oceanographic Lagrangian Observer (SOLO) float ( Davis et al., 2001 ) that contains a variable-buoyancy engine, enabling it to sink to a set depth (600 m for the iceberg study), drift at that depth, then resurface on preset time intervals. Four sediment-trap funnels and opening/closing sample cups mounted around each SOLO float collect sinking particulate matter. Additionally, an upward-looking acoustic system mounted on the float detects the presence of ice cover above. In March/April 2009, three LSTs were deployed in the NW Weddell Sea for a total of five successful missions. Four of these LST deployments were made near or under a large iceberg. The fifth deployment was made at a control site 74 km from the nearest large iceberg. Sinking particulate matter was collected on each deployment. Despite the high-risk nature of the deployments, the LSTs successfully sampled particulate matter beneath drifting icebergs.

Ship-based observations of free-drifting icebergs are hindered by the dangers of calving ice. To improve the efficacy and safety of these studies, new unmanned aerial vehicles (UAVs) were developed and then deployed in the Southern Ocean. These inexpensive UAVs were launched and recovered from a ship by scientific personal with a few weeks of flight training. The UAVs sent real-time video back to the ship, allowing researchers to observe conditions in regions of the icebergs not visible from the ship. In addition, the UAVs dropped newly developed global positioning system (GPS) tracking tags, permitting researchers to record the precise position of the icebergs over time. The position reports received from the tags show that the motion of free-drifting icebergs changes rapidly and is a complex combination of both translation and rotation.

A commercially available, small (less than 100-kg), remotely operated vehicle (ROV) was modified to image and sample the marine ecosystem surrounding free-drifting icebergs east of the Antarctic Peninsula during three field expeditions in 2005, 2008 and 2009. Modifications included fitting the vehicle with an accessory tool sled, additional thrusters, flotation and significant changes to internal wiring to support a wide array of sensors and samplers. The ROV was re-configured aboard the R/V Nathaniel B. Palmer to perform either general exploration and biological sampling (Bio dives) or water sampling (Chemistry dives). In-situ sensors and a suction sampler were used for Bio dives while a suction pump and hose were fastened along the full length of the ROV tether to enable continuous water sampling adjacent to each iceberg during Chemistry-dives. Details of the ROV system are presented along with a discussion of the 18 dives that explored the sides and bottoms of six different icebergs during the 2009 field expedition.

The Monterey Bay Aquarium Research Institute (MBARI, Moss Landing, CA) has developed a 54-cm-diameter (21-in) docking AUV and companion docking station. This program resulted in four consecutive successful autonomous homing and docking events in the open ocean, which included downloading data, uploading a new mission plan, recharging the battery, and complete power cycling of the AUV. We describe the design, simulation, and at-sea test of the homing and docking control system.

Long-term observing of our world's oceans is crucial to understanding climate change. Innovation and collaboration are needed to achieve sustainable oceanic time series.

For autonomous underwater vehicles (AUVs) to be successful in long duration deployments, they must be reliable in the face of subsystem failure and environmental challenges. The ability to detect performance anomalies and unexpected events in real time, especially in the vertical plane, is critical for the vehicle's survivability (the AUV must surface for recovery) and important for planning and vehicle operations. To this end, we have developed a vertical plane flight anomaly detection algorithm capable of comparing observed vehicle performance to references of expected behavior onboard the Tethys class long-range AUV in real time. The detection algorithm operates based on statistical characterization of training datasets that represent normal vertical plane performance. These datasets are taken directly from previous long-range AUV field operations. From this analysis we have derived a series of conditional tests that monitor representative components of the vehicle state (e.g., depth rate, pitch angle, and stern plane angle). In the months of January, February and March 2015, we conducted a series of tests in Monterey Bay, CA. The Daphne long-range AUV ran the algorithm to detect and flag vertical plane performance anomalies in real time. The AUV was successful in discriminating between expected vertical plane flight performance and anomalies during long-duration deployments lasting more than 11 days.

Thirteen minutes after sunrise on September 30, 2013,16.5 m deep in northern Monterey Bay, a white shark (Car-charodon carcharias) struck the MBARI long-range autonomous underwater vehicle (LRAUV) Tethys and left bite grooves in the pressure vessel and tooth fragments embedded in the aft fairing. Tethys survived the attack and continued her mission measuring ocean properties in that area for another week. The operators did not know about the strike until recovering the vehicle normally at the end of the deployment, when the tooth fragments and apparent bite diameter provided sufficient information to identify the shark species. We discuss the motion of the vehicle during the strike, its control response after being released by the shark, and the environmental properties it measured near the time of the strike. We also provide a damage report — although Tethys was able to complete her mission after the strike, she did not get away without a scratch. This event is a good example for recent work aimed at detecting faults and performance anomalies onboard in realtime so that operators can be notified. We show that a statistical anomaly detector correctly identifies the strike and effectively highlights it as unexpected behavior for the operator to review.

The 25 year time-series collected at Station M, ~4000m on the Monterey Deep-sea Fan, has substantially improved understanding of the role of the deep-ocean benthic environment in the global carbon cycle. However, the role of deep-ocean benthic megafauna in carbon bioturbation, remineralization and sequestration is relatively unknown. It is important to gather both accurate and precise measurements of megafaunal community abundance, size distribution and biomass to further define their role in deep-sea carbon cycling and possible sequestration. This study describes initial results from a stereo camera system attached to a remotely operated vehicle and analyzed using the EventMeasure photogrammetric measurement software to estimate the density, length and biomass of 10 species of mobile epibenthic megafauna. Stereo length estimates were compared to those from a single video camera system equipped with sizing lasers and analyzed using the Monterey Bay Aquarium Research Institute’s Video Annotation and Reference System. Both camera systems and software were capable of high measurement accuracy and precision (

This paper presents the results from recent field trials in Monterey Bay, CA which demonstrate the use of Terrain-Relative Navigation (TRN) to perform return-to-site missions using a 53cm diameter Dorado-class Autonomous Underwater Vehicle (AUV). For these tests, a series of targets were identified on a bathymetry map that were recognizable features (e.g. large boulders and outcroppings), and a trajectory was constructed for the AUV to fly over those targets (i.e. the latitudes and longitudes as defined on the map). Multiple missions were flown using a real-time TRN algorithm to identify and correct for georeferencing errors in the bathymetry map. The results were repeatable. They demonstrated that there was a 20m georeferencing error in the map. Without TRN, the targets were missed. With TRN, the AUV flew directly over the targets. Performance was independently validated using acoustic imagery from an on-board mapping multibeam sonar. These field results are presented and described. The TRN algorithm is also discussed.

This paper presents the development effort toward demonstrating acoustic tracking and homing with a long-range AUV (LRAUV) at the Monterey Bay Aquarium Research Institute (MBARI). The acoustic tracking system uses a directional acoustic transponder (DAT) from Teledyne Benthos, backed by an acoustic baffle made from syntactic acoustic damping material (SADM). We discuss sensor integration into the LRAUV system, procedures and results from an in-house calibration, and field tests with both anchored and towed transponders.

Most existing propeller-driven, cruising AUVs operate with a support ship and have an endurance of about one day. However, many oceanographic processes evolve over days or weeks, requiring propeller-driven vehicles be attended by a ship for complete observation programs. The Monterey Bay Aquarium Research Institute (MBARI) developed the 105 kg propeller-driven Tethys AUV to conduct science missions over periods of weeks or even months without a ship [1]. Here we describe a three week deployment covering 1800 km at a speed of 1 m/s, supporting sensor power levels averaging 5 watts. Unlike buoyancy driven gliders, Tethys uses a propeller that allows level flight and a variable speed range of 0.5 – 1.2 m/s. The extended endurance enables operations in remote locations like under the ice, across ocean basins in addition to enabling continuous presence in smaller areas. Early success led to the construction of a second Tethys-class AUV with a third in planning. An AUV docking station that can be mated to a cabled observatory or standalone mooring is in development to further extend Tethys endurance.

The Benthic Rover is an autonomous, bottom-crawling vehicle being developed at the Monterey Bay Aquarium Research Institute (MBARI) to conduct long-term deep-ocean ecological research. In 2009 MBARI researchers deployed the Rover on the Monterey Accelerated Research System (MARS) cabled observatory for component and operational testing. MARS is located near-shore in the Monterey Bay near Monterey, CA, at a depth of approximately 900 meters, providing the power reliability and network accessibility similar to an on-shore laboratory. By enabling immediate feedback and the ability to quickly re-program control software and re-configure mission scripts, MARS facilitates a kind of “in-situ rapid proto-testing”. MBARI researchers were able to run numerous experimental procedures and analyze results in a relatively short timeframe, converging on desired operational profiles quickly and at very low cost. This paper will cover recent development work on the Benthic Rover with emphasis on the deployment and testing on MARS.

The Tethys autonomous underwater vehicle (AUV) is a 110 kg vehicle designed for long-range, high- endurance operations. Performance goals include supporting a payload power draw of 8 W for a range of 1000 km at 1 m/s, and a power draw of 1 W for 4000 km at 0.5 m/s. Achieving this performance requires minimizing drag and maximizing propulsion efficiency. In this paper, we present the design of the propulsion system, explore the issues of propeller-hull interactions, and present preliminary test results of power consumption and efficiency. In recent underwater experiments, the propulsion system's power consumptions were measured in both Bollard pull tests and during the vehicle's flights. Preliminary results of power consumptions and efficiency are shown to be close to the theoretical predictions.

Thermoclines play a key role in ocean circulation, marine ecology, and underwater acoustics. In oceanographic surveys, it is often desirable to detect the thermocline and track its spatio-temporal variation. Mobility of an autonomous underwater vehicle (AUV) makes it an efficient platform for thermocline tracking. In this paper, we present a fully autonomous algorithm for detecting and tracking the thermocline by an AUV. The key is detection of the peak gradient of temperature. We have tested the algorithm by post-processing data from a previous Dorado AUV survey over the northern Monterey Bay shelf. We are in preparation for field tests of the algorithm on the newly developed long-range AUV Tethys.

Rover is a bottom-crawling, autonomous vehicle capable of making continuous time-series measurements at abyssal depths up to 6000 m for periods exceeding six months. The Rover control system and instrumentation suite are being designed at the Monterey Bay Aquarium Research Institute (MBARI), building on the earlier rover work of Smith and associates at the Scripps Institution of Oceanography. The vehicle weighs 68 kg in water and crawls on two wide tracks with a combined surface contact area of about one square meter; this provides good traction while minimizing the disturbance to benthic sediments. A typical mission scenario is to take measurements for a few days at each site before picking up the instruments and moving forward ~10 m to a new site. Up to fifty sites may be visited in a single mission. Engineering field tests have been performed with the Rover in the Monterey Bay in California (890 m depth), and at Station M, 220 km west of the central California coast (4200 m depth). Rover operations have been observed with the ROVs Ventana and Tiburon, and with the manned submersible DSV Alvin. Knowledge gained from these engineering deployments has resulted in numerous modifications and improvements to The Rover.

The Monterey Bay Aquarium Research Institute (MBARI) has developed an AUV docking station for a 21-inch (54 cm) diameter AUV. The system was designed for operation with cabled undersea observatories in water depths up to 4 km deep and has been demonstrated in the open ocean, though at much shallower depths. The program demonstrated successful autonomous homing and docking, data downloads, uploading of new mission plans, battery recharging, and complete power cycling of the AUV. We describe the design, and at-sea tests.

Instruments to detect the occurrence of energetic sediment transport events within submarine canyons are being developed. Submarine canyons are known to act as conduits for transporting sediment from the continents into the deep sea. Because the sediment primarily moves in discrete energetic events, determining the occurrence of events and the quantity of sediment involved in these transports has been difficult. Instruments placed at sites known to experience transport events are frequently lost, along with their data. In an effort to address this problem, the Monterey Bay Aquarium Research Institute (MBARI) has developed a Self Triggering Event Detector (STED). This presentation will deal specifically with the design, development, testing, and initial deployments of the proto-type STED system. The STEDs are placed in the axis of the Monterey Canyon at locations known to experience frequent sediment transport events. A combination of MBARI (Paull et al, 2003) and USGS (Xu et al, 2004) experiments demonstrate that the maximum currents on the floor of the canyon are less than 60 cm/sec under normal conditions. However, during sediment transport events, current velocities of over 200 cm/sec are sustained for several minutes. When a STED platform experiences currents in excess of 200 cm/sec, one meter above the sea bed, a positive buoyant science package is released to the surface. Included in this science package is an ARGOS Pop-off satellite transmitter that will time stamp the event and can be adapted to provide essential scientific data. Elements of the STED system include: a benthic platform, current detecting/triggering mechanism, Argos satellite transmitter, Homer Pro beacon, and instrument suite. The base is a robust structure constructed of heavy gauge steel which rests on the seafloor. An aluminum tower one meter in height is attached to the base and supports the triggering/release mechanism. The triggering/release mechanism rotates and functions as does a weather vane, always pointing into the prevailing current. When a current velocity exceeds the 200 cm/sec threshold, a trigger plate, forced to face into the current by the vane assembly, triggers the release, permitting the positive buoyant instrument suite to float upwards through the water column to the surface. Upon reaching the surface the ARGOS transmitter establishes satellite contact and down loads the acquired data. The unique identification of each ARGOS transmitter establishes the time and location in the canyon where an event/s has occurred. The Homer Pro beacons will allow these sites to be surveyed by ROV after an event has been detected. Requirements include: ease of manufacture (expendable), deployable and serviceable by ROV, remain functional for up to three years, survive currents up to the 200 cm/sec release threshold, and reliably release and deliver the instrument package to the surface. A goal of this project is to deploy several on these systems within the Monterey Canyon. To accomplish this it is necessary to design a system that is simple, affordable, and relatively easy to manufacture. These systems will be deployed by ROV, driving weight constrains of 91 kg in air and 45 kg in sea water. In the event of a release and the survival of the platform, the system can be rearmed by ROV intervention. To validate the system, significant testing was conducted in the MBARI 1,500.000 liter test tank. Two STED devices were deployed in depths of 290 and 520 m on May 30, 2006. On June 19, 2006 a release occurred at the 550 m site. Investigation revealed an event had taken place resulting in the transport of this platform 500 m down canyon

Nekton Research is developing a 4-7/8" diameter, 39" long UUV for the neutralization of mines in shallow water. The Ranger RN UUV can be hand-launched from a small boat, navigate on its own with GPS or acoustic long baseline navigation, and autonomously locate and home to mines. Alternatively, Ranger RN can be tracked and controlled remotely through an acoustic link. Current vehicle and field tests are described

Nekton Research is developing a cooperative multi-AUV system. This system, multi-AUV search array (MASA), will allow 3D searches and data collection with high spatial and temporal resolution in both inshore and near-shore environments. The paper discusses MASA's design.

Nekton Research and Florida Atlantic University are currently (July '02) integrating a hovering module with the Morpheus AUV. This module, which uses flexible oscillating fin thruster technology, provides Morpheus with the ability to stop, hold station and operate in heave and sway. Such capabilities will allow Morpheus to execute numerous delicate tasks such as mine classification. Herein, we discuss the foundations of this work and present results from initial sea trials.

Nekton Research and Florida Atlantic University have integrated a hovering module onto the Morpheus UUV. This module uses flexible oscillating fin thruster (OFT) technology. It provides Morpheus with the ability to stop, hold station and operate in heave and sway. These capabilities, previously unavailable, will allow Morpheus to execute delicate tasks such as mine classification. Herein, we discuss the development of the OFTs for Morpheus, results from sea trials and ideas for how to add OFTs to existing vehicles engaged in MCM operations but without the ability to hover.

The ranger micro-UUV from Nekton Research has been deployed successfully in various multi-agent mission demonstrations, including formation flying to map a salinity front and adaptive cooperation to localize the origins of test plumes. The low cost and simplicity of using the 5 kg Rangers make possible multiagent missions and algorithm testing that is beyond the economic reach of alternative UUVs. Efficiency and utility of the Ranger-UMAP multiagent system derives in part from fleet logistical interface and control software (FLICS) software created for preparation, deployment, monitoring, midmission retasking, and recovery of multiple vehicles used in cooperative missions.

Advances in animal tag technologies now offer a significant method for gathering oceanographic information throughout the world's oceans. By employing marine organisms as oceanic samplers (MOOS), vast amounts of in situ data (e.g. temperature, productivity and salinity in relation to depth and location) can be archived and transmitted via satellite or obtained directly from the tag if the tag is recovered. The beauty of this technique is that no on-board navigation system nor external propulsion supply is required. The animal performs the work necessary to transport the equipment and chooses what transect to run. The gathered data, guided by the animal's point of view, reveal secrets of the animal's life and pinpoint environmental features most important to its lifestyle. Depending on the species tagged, the animal may perform a number of tasks of great interest to oceanographers e.g. gathering data from remote regions like the poles, performing repeated deep dives, targeting specific food sources or oceanographic features and traversing massive expanses of ocean. The breadth of animal species with which this technology has been successfully deployed is growing steadily. The list includes bluefin and yellowfin tuna, white sharks, thresher sharks, whale sharks, ocean sunfish, marine turtles, seals, sea lions, and seabirds. It is hoped that the wealth of tag data already being collected worldwide can serve both the needs of the biologic and oceanographic communities alike.

A sinkhole has been identified on side-scan sonar images and from near-bottom echo sounder data in the southern Straits of Florida in 575 m of water. Sinkholes are often thought to form exclusively in subaerial environments and for this reason have been used as indicators of sea level. This sinkhole exists within a Quaternary sediment apron in water depths too great to have been subaerially exposed by Neogene sea-level lowstands, thus indicating that sinkholes can develop within the submarine environment.

Phytoplankton patches in the coastal ocean have important impacts on the patterns of primary productivity, the survival and growth of zooplankton and fish larvae, and the development of harmful algal blooms (HABs). We desire to observe microscopic life in a phytoplankton patch in its natural frame of reference (which is moving with the ocean current), thereby permitting resolution of time-dependent evolution of the population. To achieve this goal, we have developed a method for a Tethys-class long range autonomous underwater vehicle (AUV) (which has a propeller and a buoyancy engine) to detect, track, and sample a phytoplankton patch in buoyancy-controlled drifting mode. In this mode, the vehicle shuts off its propeller and actively controls its buoyancy to autonomously find the peak-chlorophyll layer, stay in it, and trigger water sampling in the layer. In an experiment in Monterey Bay, CA in July 2015, the Makai AUV, which was equipped with a prototype 3rd-generation Environmental Sample Processor (3G-ESP), ran the algorithm to autonomously detect the peak-chlorophyll layer, and drifted and triggered ESP samplings in the layer.