Wet and wild: builders try not to get in over their heads renovating the Pine Knoll Shores aquarium.

• Position: BUILDING NORTH CAROLINA

Nature spent millions of years building the seabed that the U-352 settled onto after the Coast Guard sank the German sub off Cape Lookout in 1942. In the state aquarium at Pine Knoll Shores, Clancy & Theys Construction Co. re-created it within a few months, capped by a 10-hour continuous pour of more than 350 cubic yards of special-mix concrete, bulk to bear 1,200 tons of seawater behind three acrylic windows--one of them 10 feet tall, 65 feet long and 8 1/4 inches thick--in the Living Shipwreck exhibit's 306,000-gallon tank.

"Usually a contractor is doing everything he can to keep water out of a building," says David Michael, senior project manager with the Wilmington office of the Raleigh-based builder. "Here you're trying to contain water inside a building." Besides being wet, seawater is heavy--64 pounds a square foot--and corrosive, and it was everywhere in the $25 million renovation, which shut down the aquarium nearly 2 1/2 years and tripled its size from 29,000 to 93,000 square feet.

The aquarium's five galleries depict habitats from the mountains to the sea. To bring the outside inside, Clancy & Theys crews and subcontractors built a 32-foot waterfall and replicated sections of a river, creek, reservoir, cypress swamp, tidal pools, even a 50,000-gallon tank depicting the resting place off Beaufort Inlet of what might be Queen Anne's Revenge, the pirate Black-beard's flagship. All this water required not only specially designed plumbing, electrical and mechanical systems but also heavy-duty heating, ventilation and air conditioning to handle the humidity.

Builders began with more than 600 pages of plans prepared by BMS Architects of Wilmington. Among their tasks was getting water in and out of the building. They put in a $140,000 system to pump seawater from the sound--it's expected to save the aquarium, which had been making saltwater, at least $80,000 a year--and a sewage plant to treat wastewater from the kitchen and toilets. About 85% of it then can be returned to flush commodes and urinals. And not only did they have to build on sand but nearly on marsh. "I climbed up on top the other day," Michael says, "and from that vantage point you realize that you are at the edge of the wetlands at every corner of this building."

In addition to the tradesmen and laborers found on most big construction jobs, the project required special contractors to install the life-support systems, do decorative gunite work, install graphics displays...