An Argentine submarine went missing last week about 270 miles off the coast of Argentina, carrying 44 crewmembers. It had left Ushuaia and was on its way to Mar de Plata.

The sub was supposedly returning to base after reporting battery failure when it got lost.

Seven communication attempts from the sub occurred Saturday, and on Monday the Argentine Navy said it is analyzing a noise that might have come from the sub. The noise originated about 220 miles off Argentina’s coast at 650-ft. depth.

ST spoke with Andy Sherrell, the owner of Sherrell Ocean Services, a consulting company for underwater mapping and search and salvage projects that was hired by the Australian Transport Safety Bureau to work on the search for Malaysian Airlines Flight 370, which went missing in the Indian Ocean in March 2014. Sherrell talked about the search process in general.

From your experience, what are the best methods to try to find this sub?

They’re doing an aerial search right now and using satellite imagery as well. That’s a good place to start, and analyzing any communication that was received from the sub prior to loss of communication. It’s important to try to triangulate information from that.

Aerial search is good to cover a wide area quickly on the surface. Two-hundred-fifty miles offshore is not too, too bad. It’s certainly accessible by aircraft.

The weather was pretty rough. That makes it more difficult. It’s possible that there’s nothing on the surface to be detected, so then they would use underwater vehicles to locate the sub. Underwater listening equipment would be used to see if they can hear any noises emitted from the submarine, either generating from sailors banging a wrench across the hall or an emergency beacon they can use to transmit a noise that can be heard from a hydrophone on the surface or towed beneath the surface. Underwater equipment like deepwater towed side scans and underwater AUVs can help find it on the seafloor.

Can you draw similarities to the search for MH370?

That’s pretty much how it went with MH370. It started with aerial search to look for surface debris than moved onto listening for the black box and underwater acoustic noise. When that failed, we continued with deep-tow side scan vehicles, AUVs and ROVs to map the seafloor to see if we could find remains or wreckage.

Obviously, this is very time critical with the submarine. It’s a bit difficult to get some of those assets to a certain area quickly with the severe weather.

Can you give us an update on MH370?

I’ve been involved in the search for about three years now. We’ve covered about 120,000 square kilometers. That’s a large area to look for something on the seafloor. Similar to this, the loss information was very minimal, and the weather and sea conditions, there are parallels there. The southern Atlantic Ocean is like the southern Indian Ocean. There are some parallels with the type of equipment and underwater mapping.

The search was suspended in January.

How long do you think the sailors have to survive?

Seven to fourteen days—that’s just what I’ve seen in the news.

Do you think this will be an international effort?

It will be a worldwide effort. It appears to have already started that way. There’s a lot of countries already involved. In a matter of life and death like this with an especially critical time frame, anybody that can is offering any support. I think they’re doing everything they can right now.

—Aileen Torres-Bennett