Program 284a: Diving Adventures; Instant Cities; Unconquered Amazon

This show goes to great depths: A diving enthusiast highlights the underwater world, from the turquoise coasts of Central America to the cold jade waters of Puget Sound. Then NPR's Steve Inskeep explains what Karachi showed him about the world's mushrooming mega-cities. And author Scott Wallace describes his trek deep into the Amazon, and the efforts to protect the fierce Arrow people from contact with the outside world.

• Travel writer Amanda Castleman, contributor to writers.com
• NPR Morning Edition co-host Steve Inskeep, author of "Instant City" (Penguin)
• Scott Wallace, author of "The Unconquered" (Crown)

• Amanda Castleman's website includes links to her Road Remedies travel blog updates. She also teaches online writing courses through the Writers.com website. 
• Amanda considers Anthony's Key Resort in Roatan, Honduras as one of the world's best scuba centers. 
• The Bonneville Seabase is the location in Utah for snorkeling and scuba diving to view exotic salt water fish. 
• Steve Inskeep's book, "Instant City:  Life and Death in Karachi," is now available in paperback from Penguin-Random House.
• NPR has a bio of Steve Inskeep on its website, with links to audio features he filed in April 2014 from the US-Mexico border, and March 2014 from Syria.    
• Steve Inskeep refers to Bill Bishop's book "The Big Sort," and the writings of the late Chicago columnist Mike Royko, when noting how geographic demographic changes are polarizing Americans. 
• Scott Wallace also wrote about the work of Sydney Possuelo for National Geographic. 
• Scott Wallace's website includes more of his writings and photographs about uncontacted populations, and a short video about his book "The Unconquered."