Along the southern shore of Dauphin Island, troops from the Alabama National Guard splash in the warm shallows of the Gulf of Mexico. But this is no holiday trip.
In fatigues and boots, they use large metal stakes to secure wire mesh boxes to the wet sand.
Each box is lined with a tough green fabric. Looking back down the beach, it almost looked like angular tropical vegetation hugging the shore as far as the eye could see.
In fact the boxes stretched for two miles. It has taken troops three days to place them, and one soldier said they had seven more miles to go. In the heat and humidity, it looked like very hard work.
The troops were laying coastal defences. Once in place, the boxes will be filled with sand. A chemical that causes oil to solidify and makes it possible to scoop out will then be laid on top.
The US military uses similar boxes in Iraq and Afghanistan as "blast walls" - barriers to protect against explosions.
And Capt Marcus Young, who was leading the work, believes this is a conflict situation too.
"We know the enemy is coming and we are just waiting for it," he said.
"That's kinda different for us. We are used to attacking and not waiting to be attacked... The oil if it reaches the shore line is going to destroy all the vegetation."
Further along the shore a narrow strip of asphalt divides the Gulf coast beach from the more grassy banks of the Mississippi Sound. Wooden houses perch enviably on stilts.
It is so low-lying that sea swells often cover the road. This fragile strip of paradise is under threat.
A constant stream of large lorries thunder up and down, dumping large piles of sand onto the Gulf side of the road. Diggers then shovel it into mounds at least a metre (3ft) high.
They are constructing a barrier to absorb as much oil as possible and stop it getting into the sound.
One homeowner said he and his family had survived Hurricane Katrina but they did not know what damage the oil spill might do.
'Trust in God'
It has had some effect already. There was only one person on this pristine white beach.
Tour operators say they have already had cancellations. Meanwhile the region's other big industry - fishing - is in disarray.
Unloading his catch of mullet from a small open boat, Richard Collier, a second generation fisherman, says: "Ever tried them smoked? They're the best."
He fishes in the area between the shore and the oil slick, but does not know how much longer he will be allowed to do so.
Already fleets used to deeper water - where the spill is - have been banned from fishing in coastal waters and must head further afield.
Ironically, because of this, Mr Collier gets a higher price for his fish right now. But he worries.
"This is my livelihood. I feed my babies from this. If [the oil] comes and they shut me down, I want to know where my pay cheque is coming from. BP owes me a job," he says.
John and Sonia Amick normally fish red snapper 15 miles (25km) offshore, but were preparing to sail 180 miles in search of grouper.
"I'm still uncertain," Mrs Amick said. "I trust and believe in God that He will take care of us but we are going to waters we don't fish normally and I just hope the oil doesn't reach there."
On the dock, the son of a wholesaler who buys their catch helped pack and weigh some fish.
When asked what his concerns were, he looked up with tears in his eyes and said: "This is my home."