A crew mapped the sea floor off Maryland's coast to find suitable places to put wind turbines. (Kenneth K. Lam/Baltimore Sun video)

OCEAN CITY — The high-rise towers of Maryland's Atlantic beach resort were blips on the horizon from 13 miles offshore. Except for a distant container ship coming out of Delaware Bay, the Scarlett Isabella was practically alone as it cruised slowly through the gently rolling sea.

But most of the 15 scientists and technicians aboard the 138-foot vessel were focused on what's beneath the waves, eyes glued to a bank of computer screens tracking signals from sophisticated electronic gear deployed overboard.

The crew has been working almost nonstop since late June to map a 94-nautical-square-mile expanse of sea floor off Maryland's coast, gathering data that could help place up to 40 huge wind turbines there to generate power. Weather permitting, they hope to be done next week.

"It's starting to get real, this offshore wind stuff. We've got boats, we've got data," said Andrew Gohn, senior clean energy program manager for the Maryland Energy Administration.

The geophysical survey of the ocean floor and what lies beneath it is being conducted for the state by Coastal Planning & Engineering Inc., of St. Petersburg, Fla. Maryland officials hope the data gathered through the $3.5 million contract will help prospective wind energy developers figure out where to build turbines.

"We're mapping the sea floor and subsurface shallow geology beneath the sea floor ... to determine if it can support the construction of turbines — and if so, in what fashion," explained Beau Suthard, client program manager for the firm, a subsidiary of CB&I, a large energy infrastructure firm with headquarters in Texas and Europe.

Though turbines have been generating power for years off the European coast, none has been built in U.S. waters. It could still be years, if ever, before any go up.

There's been an uptick in regulatory activity lately, though. The federal Bureau of Ocean Energy Management held the nation's first auction last month to lease 165,000 acres for wind development off the coasts of Rhode Island and Massachusetts. Another auction is scheduled next month for an area off Virgina.

The federal agency is expected to publish a lease sale notice for the Maryland offshore wind area this fall, with plans to solicit bids and award one or two leases next year.

Gohn said the survey data gathered this summer would be useful to a winning developer.

"This is to accelerate the process a little bit," explained Gohn. "In a sense we're acting as a proxy for the developers, who are not yet known."

Using sonar, seismic and magnetic imaging gear, the contractors have been painstakingly gathering data as the Scarlett Isabella methodically crisscrosses the wind energy area.

Echosounders mounted on either side of the vessel measure the water depth, while a pair of sleek "fish" towed astern — sidescan sonar and a magnetometer — scan the bottom for unusual features and anything metallic that might indicate a shipwreck or other hazard to avoid. Two other systems, emitting electrically induced "chirps" and sparks into the water, look at the geologic makeup of what lies beneath the ocean floor.

Because those seismic signals are loud enough to harm any nearby marine mammals, a pair of lookouts on the bridge scan the water in all directions and report any sightings. Federal rules require all sonic gear be turned off if any whales or turtles come within 500 meters, while the sonar must be powered down to its lowest level for a time if dolphins swim close.

Conservationists have expressed concerns about the potential impacts of offshore wind turbines on marine mammals, but also on sea birds and bats. Steve Holmer with the American Bird Conservancy said some coastal areas also happen to be migratory flyways for birds.

Holmer said areas further out to sea might be more suitable for placing the turbines. But, he said, "It just appears there's a headlong rush to get these things built."

The survey off Maryland's coast has seen some fish and marine mammals, but few birds, said Suthard.

"We've seen a couple pods of dolphins, we've seen multiple sea turtles, loggerhead turtles, green sea turtles. We've seen one humpback whale," he reported. "We think we've seen one pilot whale, and we did see one whale off in the distance we were unable to identify because it was too far away."

The lookouts, student interns from the University of Maryland Eastern Shore, also have spied sharks and some big tuna swimming around the vessel.

"It gets boring when you don't see anything, but it makes it that much more special when you do see something," said Blake Bussard, a junior majoring in a joint marine biology program at Salisbury University and UMES.