joining me now is national geographic explorer tara roberts. retty cool. but when i read that you've written this book and that you went on this journey after visiting a museum in washington, i had to ask, why were you so inspired by that visit? >> yeah, so i visited. >> the national. >> museum of african american history and culture, which is a beautiful, beautiful museum. but in it, on the second. >> floor. >> there was a picture of a group of primarily black women in wetsuits on a boat. and i had never seen a picture of black. women in wetsuits on a boat before. so it really sparked something in me. and then when i read about what they were doing, i learned that they were a part of this group called diving with a purpose, and that what they did was search for and help document slave shipwrecks around the world. i was blown away by this work and just wanted to be a part of it some sort of way. >> you've traveled across the world, tara. you've been to four continents. you've been tracing these vessels of the trans-atlantic slave trade. how has