{"id":19362,"date":"2026-09-06T07:30:18","date_gmt":"2026-09-06T11:30:18","guid":{"rendered":"https:\/\/www.autonocion.com\/us\/?p=19362"},"modified":"2026-09-06T05:35:49","modified_gmt":"2026-09-06T09:35:49","slug":"drone-slides-battery-sleeps-seafloor","status":"publish","type":"post","link":"https:\/\/www.autonocion.com\/us\/drone-slides-battery-sleeps-seafloor\/","title":{"rendered":"A 250-pound drone keeps working through 30-foot seas that would send a survey ship back to port, and the only moment weather can touch it is when it surfaces every six hours to talk, so if the pickup boat cannot come out it lands on the bottom and sleeps"},"content":{"rendered":"

You can buy an underwater drone that will happily stay down for weeks. Getting it back is harder than the spec sheets let on, because a robot bobbing on the surface in a gale is an expensive object waiting for a boat that cannot safely come out to it. NOAA Fisheries<\/a> published a writeup on August 31 about two robots it has been flying over the Mid-Atlantic seafloor, and tucked inside it is the most practical answer to that problem I have read in a while.<\/p>\n

If the weather turns, the robot lands on the bottom and goes to sleep.<\/p>\n

The two vehicles are named Stella and Polaris. The Woods Hole Oceanographic Institution owns both and runs them, the platform came off the drawing boards at the Monterey Bay Aquarium Research Institute, and NOAA borrows them for its seafloor imaging work. Between June 30 and July 6 the pair covered more than 200 nautical miles (roughly 230 miles) of track lines loaded in before launch, and came back with more than 68,000 photographs of the bottom. Scientists went through those pictures and logged skates, squid, snake eels, crabs, fish and a lot of sea scallops.<\/p>\n

So what is one of these things?<\/h2>\n

Picture a torpedo about 9 feet long and 12 inches across, weighing 250 pounds. NOAA calls it a long-range autonomous underwater vehicle, or LRAUV, and the entire design argument is that two people and a small boat can put it in the water. No crane. No chartered research vessel. It dives to 984 feet, its standard lithium batteries run for about a week on one of these imaging missions, and it finds its way around in the dark with a compass and a doppler velocity logger, a sensor that works out how fast you are going by bouncing sound off the seafloor and listening to what comes back.<\/p>\n

One number I am skipping: NOAA’s page gives the cruise speed two different ways inside the same sentence, so I am leaving speed out and sticking to the rest of the page, which is consistent.<\/p>\n

\n
\n
Weight<\/div>\n
250 lb<\/div>\n
Per vehicle. Two people and a small boat put it in the water. No crane.<\/div>\n<\/div>\n
\n
Size<\/div>\n
9 ft<\/div>\n
Length, at 12 inches in diameter. Sensors all live in the nose section.<\/div>\n<\/div>\n
\n
Max depth<\/div>\n
984 ft<\/div>\n
Dive limit NOAA lists for the vehicles it operates on scallop surveys.<\/div>\n<\/div>\n
\n
Endurance<\/div>\n
~1 week<\/div>\n
Standard lithium battery life on a HabCam imaging mission.<\/div>\n<\/div>\n
\n
ACTIVE<\/div>\n
2026 mission<\/div>\n
68,000+<\/div>\n
Seafloor photos from Stella and Polaris combined, June 30 to July 6, 2026.<\/div>\n<\/div>\n<\/div>\n

It steers by moving its own battery<\/h2>\n

Most underwater vehicles aim their nose with fins and hold depth by fighting the water with a propeller, which burns power the whole time. Stella and Polaris do a good chunk of that work almost for free. To tilt the nose up or down, the vehicle physically slides its internal battery pack forward or backward, shifting its own center of gravity the way you shift your weight in a kayak. To sink or rise, it runs a buoyancy engine, which pumps mineral oil out of the pressure housing to make the vehicle denser and pumps it back in to make it lighter. A thruster, an elevator and rudder fins handle the actual driving. NOAA describes the result as a hybrid with the endurance of a glider and the electrical headroom of a propeller-driven vehicle, and the payoff is that it can afford to carry stereo cameras and LED lights instead of a lonely temperature probe.<\/p>\n

\"MBARI
Credit: MBARI<\/figcaption><\/figure>\n

Scientists bolt on whatever else a mission needs. Stereo cameras photograph and measure scallops, a CTD instrument reads the water column, and an optical sensor tracks clarity and phytoplankton. The vehicle also logs temperature, salinity, dissolved oxygen and currents as standard.<\/p>\n

NOAA does not say what either vehicle cost, which is the one number I would have liked.<\/p>\n

So what happens when the weather turns?<\/h2>\n

A normal mission has the drone surface every six hours to check in over satellite with its position and a status report. Satellites do not reach through seawater, so that surfacing is the only moment anybody hears from it. The rest of the week it is flying programmed track lines in the dark, taking pictures.<\/p>\n

Surfacing is also when the sea state starts to matter. Cameron Fairclough, an advanced technology specialist at the Northeast Fisheries Science Center, says in the writeup that the team has had a vehicle working through 20 to 30 foot seas, conditions that would send a survey ship back to port, and that the swell only becomes an issue when the drone comes up to communicate or be recovered. So the crew books the pickup for a safe weather window. If that window slips, they can park the LRAUV on the seafloor to sleep and conserve battery life<\/q> until somebody can safely make the trip out.<\/p>\n

Sitting on the bottom costs the vehicle almost nothing. Its electrical system shuts off the power-hungry sensors when they are not collecting, the water down there is calmer than the surface, and the drone simply waits. You have seen the same reasoning in bigger machines: Northrop Grumman built Manta Ray to anchor on the ocean floor and sleep there for months<\/a>, and Saipem’s Hydrone-R spent 240 straight days living on the seabed of the Norwegian Sea<\/a>. Stella and Polaris are far smaller and their reason is more mundane. Somebody eventually has to drive out in a boat and lift them back on deck.<\/p>\n

The scallop fleet is having a lean year<\/h2>\n

So why does a federal agency care this much about photographing shellfish? The money is why. NOAA puts 2023 commercial sea scallop landings at 27.4 million pounds worth $360 million, which makes it the largest wild scallop fishery in the world. Those seafloor images feed abundance estimates, and abundance estimates decide how many days boats are allowed to fish.<\/p>\n

2026 has been tight. Framework Adjustment 40<\/a> took effect on April 1 and set 36 days at sea for full-time limited access permit holders and 14.4 for part-timers, and it opened no access areas at all for the fishing year. Area II and both Nantucket Lightship rotational areas are closed. When the allocation is that thin, every stretch of bottom the survey misses because of weather turns into a hole in the estimate.<\/p>\n

Offshore wind is the other reason NOAA wants these drones. A large vessel dragging a camera sled on a cable cannot work safely inside a wind farm, and the survey has to cover that ground anyway. NOAA launched an LRAUV off a 25-foot boat out of Buzzards Bay, Massachusetts and ran research tracks inside and around the South Fork Wind Farm, roughly 35 miles east of Montauk, New York, collecting data it had no other way to get.<\/p>\n

NOAA is buying its own next year<\/h2>\n

Everything so far has been done with borrowed hardware. NOAA says it expects delivery of its own LRAUV next year, built by Saab, which licensed the MBARI design for the US market in 2023. The program has climbed in visible steps: camera development started in 2021, test surveys ran in 2023, the 2024 data went through the Council’s technical review and into the annual abundance estimates, a second camera system was built in 2025, and this summer both vehicles worked independently of the towed HabCam survey for the first time.<\/p>\n

The wish list for the Saab vehicle is broader than scallops. NOAA lists plankton studies, tracking whale foraging with passive acoustics, active acoustics for fish populations, and water sampling for environmental DNA. That last one is a genuinely useful trick, since a drone can vacuum up a water sample and let a lab read which species have recently swum past.<\/p>\n

The New England Fishery Management Council’s Scallop Advisory Panel and Plan Development Team<\/a> meet on September 9 to review the 2026 survey results and begin shaping specifications for the 2027 and 2028 fishing years. Stella and Polaris took 68,000 of the pictures behind that conversation.<\/p>\n","protected":false},"excerpt":{"rendered":"

You can buy an underwater drone that will happily stay down for weeks. Getting it back is harder than the … <\/p>\n

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