Deep Trekker Inc. featured in "The Wall Street Journal"

Underwater Drones Are Multiplying Fast
Robots Are Invading the Sea for All Kinds of Inspections—With an Eye on Prey

The next army of unmanned drones are scurrying beneath the ocean’s surface.

Hundreds of small camera-equipped robots developed by a range of companies are sending video and other data to laptop and tablet screens above.The next army of unmanned drones are scurrying beneath the ocean’s surface.

What began as a niche industry for wealthy hobbyists has matured into a fast-growing market catering to a wide variety of industries and government agencies.

A VideoRay underwater vehicle equipped with a camera and radiation detector inspects the hull of a ship.

Unmanned marine vehicles have been around for years-the U.S. Navy and the Coast Guard, for example, use them to help detect mines and thwart drug smugglers. Big military contractors such as Boeing Co. BA -1.97% and General Dynamics Corp. GD -1.17% offer torpedo-like underwater vehicles for the military and other government agencies.

Now, a new wave of independent companies are developing cheaper, smaller models-typically the size of a football-meant for commercial and recreational use, from inspecting oil rigs and fish farms to helping hunt for sunken treasure.

But as the industry grows, drone-making companies are also running into hurdles. The companies must figure out how to market these technologies for applications beyond traditional uses, compete with bigger defense contractors, and keep costs low enough to appeal beyond deep-pocketed buyers.

Operating machines underwater is no easy task. Motors sometimes malfunction, causing the robots to sink, or a previously undiscovered crack can cause critical leaks. Last week, a team from Memorial University in Newfoundland lost contact with an autonomous underwater vehicle that looks like a yellow torpedo and was worth about $165,000.

Then there is the prey. Two years ago a shark attacked a sea-gliding robot piloted by Liquid Robotics Inc., causing the device used to collect data for BP BP.LN -1.25% PLC to malfunction. Sam MacDonald, co-founder and president of Ontario company DeepTrekker Inc., said a barracuda “took a quick bite” out of a demo device in Antigua “but decided against making it meal.” The robot survived.

“Because of the dangers of doing things underwater you’re going to see these robots do more practical things,” said Durval Tavares, the chief executive of AquaBotix Technology Corp.

His company sells an underwater remote-operated vehicle, or ROV, called the HydroView, which can be controlled from a laptop or mobile device and cost between $4,000 and $8,000. Mr. Tavares, who started the Fall River, Mass., company in 2011 after 20 years working at the U.S. Navy Laboratories, says he has sold near 200 devices to customers including a Florida police department that used them for underwater inspections.

One of the bigger companies in this field is VideoRay LLC, which sells its ROV to coast guards, the U.S. Corps of Engineers and other commercial and military bodies. The Pottstown, Pa., company’s devices have been used to search for underwater mines, assess hurricane damage and make hull inspections for oil companies.

VideoRay uses specially made software, joysticks or smartphones to pilot its robots. Stripped-down ROVs sell for $7,000, but the versions sold to governments and oil companies are priced around $150,000. Scott Bentley, VideoRay’s co-founder and president, says the 40-employee company sells from 200 to 400 underwater drones a year and makes about $10 million in sales annually.

Both Aquabotix and VideoRay are working on their own version of “automated underwater vehicles,” which don’t require someone remotely controlling them the whole time.

Another sign of popularity in the devices is a growing community of ROV builders who want the technology to be open sourced, available for scientists and explorers who can’t afford more expensive models.

OpenROV sells an underwater ROV kit for $850. Co-founder David Lang said the Berkeley, Calif., company has sold several hundred so far to scientists and hobbyists. The project is “like making a smartphone waterproof and giving it thrusters,” Mr. Lang said.

“We want to be able to have an ROV that is approaching the performance of some of these more expensive commercial ROVs at 1/10th of the cost. “These ROV makers are finding a diverse group of interested customers.

DeepTrekker, which makes an 18-pound ROV starting at $3,000, has sold devices to customers such as Florida Power and Light Co. to examine inside a nuclear reactor and Disney DIS -1.93% World to inspect water filtration systems.

At a recent military trade show in Canada, DeepTrekker’s Ms. MacDonald said several military agencies approached her about the ROV. One agency asked if she could put a weapons deployment system on it. The company is working on that request.

Ms. MacDonald has also had more nefarious-seeming inquiries. One potential customer asked questions about DeepTrekker’s maximum payload and whether the ROV could be operated from 10,000 feet away. Ms. MacDonald suspected they might be drug-runners, but they never made an offer.

Write to Will Connors at william.connors@wsj.com

A version of this article appeared June 25, 2013, on page B4 in the U.S. edition of The Wall Street Journal, with the headline: Unmanned Drones Take a Dive.