Barney and Gemma meet the sports stars of the sea - sprinters, jumpers and even gymnasts!
Barney and Gemma show that coral reefs are like our cities - and everyone has a job to do.
From diving for lobsters in shark-infested waters to fly-fishing for trout, Gordon gets a full adventure before facing off against Analiese Gregory.
Joanna completes her Cuban journey in Guantanamo. Fifty-seven miles across the Windward Passage to Haiti, she discovers a very different country. She heads off to Cap Haitien to discover its history and the reality of life in Haiti.