STEVE INSKEEP, host:
Off the California coast today, a robotic machine will be exploring the ocean floor. It's documenting the remains of a U.S. Navy airship.
Seventy-one years ago, the USS Macon dropped out of the air into the water near Big Sur. The remains sit about 1,000 feet down. The leaders of this expedition include Chris Grech, of the Monterey Bay Aquarium Research Institute.
Mr. Grech, where are you?
Mr. CHRIS GRECH (Monterey Bay Aquarium Research Institute): Okay, we're sailing south, just off the coast of Big Sur. We're about three miles off the coast and we're going about 10 knots.
INSKEEP: And you are looking for this airship. What was the Macon like when it was flying?
Mr. GRECH: It was probably something that most people can't even imagine these days. It would be a 785 foot long airship that's about 140 feet in diameter that's lumbering through the skies at 40 to 70 knots. So it was a rather slow moving machine floating up in the air, and it used to produce quite a roar when it went over the ground.
INSKEEP: This is the era, this is the 1930s, the era of the Hindenburg. That's the kind of big airship we're talking about here, right?
Mr. GRECH: That's correct. It's a very impressive sight that I think people in the '30s would just stop what they were doing when they saw these airships come by and focus their attention and gaze in kind of amazement at these large airships.
INSKEEP: How did the U.S. Navy use it?
Mr. GRECH: Well, the main purpose of these airships were for long-range scouting. They would actually put biplanes inside of the airships and they would fly in and out like a flying aircraft carrier and do long-range scouting with the biplanes.
INSKEEP: And what went wrong?
Mr. GRECH: What went wrong on February 12th was - 1935 - was they had like a wind shear or wind gust that tore away a rudder, which punctured some aft helium cells which provide lift for the airship. And as the airship lost its lift, the captain did a series of maneuvers to try and regain control, but basically had to put it in the water and try and get his crew off.
INSKEEP: What happened to the crew of the Macon when it went down?
Mr. GRECH: There was a total crew of 83 onboard and all of them made it off except for two. One of them jumped prematurely with a lifejacket on and they weren't able to find him. And the other individual I think ran into the wrong the direction on the ship and probably was suffocated from helium exposure.
INSKEEP: Helium, because that's what kept the thing in the air?
Mr. GRECH: Exactly. The captain of the airship decided to put it in the water because the Navy fleet was close by, and he did a great job of getting it down and getting most of the crew off successfully.
INSKEEP: So what's left of this airship from what you can tell so far?
Mr. GRECH: Okay, so right now it's pretty much been flattened out, you might say, that these airships were these long, big open frames and now what's happened is that the framework is all flattened out on the seabed. So now the planes in the hangar area that were on the bottom of the airship are now actually the tallest part of the debris field on the seabed.
She rested on a plateau off the coast and on either side are pretty sharp canyons that go down much deeper. But we were in luck when the Macon went down in that it rested on the top of this plateau.
INSKEEP: Is this wreck a scene for a lot of marine life, the way that shipwrecks often become?
Mr. GRECH: Oh, yes. Originally, that's how I found the location of this airship, was contact through a fisherman. The site was very plentiful for a fish called black cod, and there was a fisherman here that used to lay his traps down at the site and that's how we were able to find it.
INSKEEP: Can I ask why your institute, the Monterey Bay Aquarium Research Institute, finds it important now to be exploring this wreckage?
Mr. GRECH: Well, we've got two excellent partners that are supporting us and actually were the catalyst for this latest trip. NOAA and the Monterey Bay National Marine Sanctuary asked us to come down here and survey the site and detail it for a cultural heritage site for preservation and long-term study.
INSKEEP: Well, Mr. Grech, thanks very much.
Mr. GRECH: It's been great talking with you.
INSKEEP: Chris Grech is deputy director of marine operations for the Monterey Bay Aquarium Research Institute. He's on a vessel out near Big Sur. And you can see the USS Macon in flight and follow the underwater expedition at npr.org.