MICHEL MARTIN, HOST:

And finally today, a key chapter in the origin story of Africans in America took place over water. Historians estimate that some 36,000 ships brought nearly 12.5 million Africans across the Atlantic Ocean, according to the Transatlantic Slave Trade Database. But not all survived. Somewhere between 500 and 1,000 ships are believed to have wrecked, but only a handful have been found and documented. This is according to Tara Roberts of a new podcast from National Geographic called "Into The Depths." She not only follows a group of Black divers, historians and archaeologists as they try to recover as much as they can of that lost chapter. She decides to become one of them.

(SOUNDBITE OF PODCAST, "INTO THE DEPTHS")

TARA ROBERTS: Through these ships, we could bring lost stories up from the depths and back into collective memory. Just as important, it was a way to help me understand my roots, my own family's history and where I and we belong as Black Americans right now.

MARTIN: Tara Roberts is executive producer of "Into The Depths," and she is with us now to tell us more about it. Tara Roberts, welcome. Thank you so much for joining us.

ROBERTS: Wow. Thank you so much for having me, Michel.

MARTIN: So first, I'm just going to ask you to give us the short version of what you shared in the podcast, how you kind of just dropped everything, quit your job to pursue this project. So tell me how you heard about it and why you think it had that hold over you.

ROBERTS: Yeah. It was completely by accident, actually. I happened to visit the National Museum of African American History and Culture in D.C. And I ended up on the second floor, which is this tiny floor that most visitors, I think, skip. But on that floor, there was a picture of a group of primarily Black women on a boat in wetsuits. And it really was that picture that captivated me. It stopped me in my tracks because I'd never seen a group of Black women on a boat in wetsuits before. So when I went to find out, who are they? And what are they doing? I found out that they were part of this group called Diving with a Purpose and that part of their mission was to search for and help document slave shipwrecks around the world. And from that moment, I was hooked.

MARTIN: And to the purpose, why do you and why do they think it's important to unearth these histories and document the remains of these ships from the transatlantic slave trade - to the degree that's possible after all these centuries?

ROBERTS: Well, I think you hit on it when you gave the stats earlier. If there are as many as a thousand potential wrecks out there but only a handful have been found, that means there's an enormous amount of history that's just missing.

MARTIN: And one of the key figures in this movement is Dr. Albert Jose Jones. He co-founded the National Association of Black Scuba Divers. I just want to play a clip of him describing a particular moment documenting the wreckage of the Henrietta Marie. It's a ship that carried enslaved people and was found off of Key West in 1972. That might be a name that some people know, and here's the clip.

(SOUNDBITE OF PODCAST, "INTO THE DEPTHS")

ALBERT JOSE JONES: It felt like you were touching the souls of your ancestors when you were down there, and it involves people that could be your own family.

MARTIN: Could you talk a bit more about this dive and Dr. Jones's role in your work and just what an emotional experience that it can be to connect with these wrecks?

ROBERTS: Yeah. Dr. Jones is considered the grandfather of Black scuba diving. He started the first Black diving club, and he started that, Michel, in 1959. So Black folks have been diving for quite a while. But Doc dove on this site, and when he was down there, he decided that it needed to be memorialized in some way. So he came back, and he got members of the National Association of Black Scuba Divers together, and they raised funds to put a plaque down at the site to honor the people who died in the Middle Passage. And I think that that is often skipped over in our history books, how many Africans died in the Middle Passage. The number is 1.8 million Africans died in that passing. And who's honoring them?

MARTIN: I have to say I looked it up, and that's the population of Phoenix.

ROBERTS: Wow.

MARTIN: So if you can think about - it's larger than the population of Philadelphia. It's larger than the population of San Antonio. It's larger than the population of Dallas - so to put that into some context of how many souls are lost to that - to the bottom of the sea in that passage. So I'm just wondering what that was like for you.

ROBERTS: Yeah. There are definitely sad notes in this work when you're faced with the artifacts of the past. But overwhelmingly, I felt so empowered to be part of helping to raise this history from the depths, to bring these people back into memory.

MARTIN: So before we let you go, you know, we are in a moment when some people don't want to hear about this history at all, from what we are observing. There are certain movements in many parts of the country to stop teaching certain things, to withdraw certain books from the shelves, withdraw certain stories from the curriculum. And I'm just wondering what you would say to those people, based on the work that you and the others have done.

ROBERTS: I would say that the truth about the Middle Passage and the global slave trade is that it's huge history. Like, it's global history. It's not just Black people's history. There were four continents involved in the global slave trade. It's Europe. It's Africa. It's South America. It's North America. It happened over 400 years. And I - what I am understanding through this work is that there's a way to examine the past that's not inside of shame. It's not inside of anger, and it's not inside of guilt. But we have to look at it, I think, to be able to go through it so that we can heal this space.

MARTIN: That was Tara Roberts, National Geographic explorer and host of the podcast "Into The Depths." Tara Roberts, thank you so much for speaking with us.

ROBERTS: Thank you for having me, Michel.

MARTIN: And if you want to hear more about this project, you can tune in to NPR on the Clubhouse app on the next two Wednesdays in February at 8:00 p.m. Eastern Time, 5:00 p.m. Pacific. NPR's Karen Grigsby Bates will be speaking with Tara and other National Geographic explorers about their work documenting slave trade shipwrecks.

(SOUNDBITE OF STEVIE RAY VAUGHAN AND DOUBLE TROUBLE'S "LENNY") Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.