In Cuba, Robson goes for the Inshore Grand Slam, where he must catch three species of fish from a set list in a single day. But wind and rain threaten to jeopardise the attempt.
Bass is big in America so Robson is heading to Michigan for the coveted Bass Grand Slam. He's on one of the best bass fishing lakes in America, but is it enough to secure the prize?
Robson is in Costa Rica going for an epic Billfish Grand Slam. He must travel 12 hours out to the best fishing spot, so he has just one shot at his mission.
Robson grew up hearing tales of the Kenai River in Alaska and this time, he's there, fulfilling a childhood dream and going for the Salmon Grand Slam on one of the best salmon fishing rivers in the world.
This week Robson has come to a remote island off the west coast of Africa to go for his Guinea Bissau Grand Slam. To stand any chance, he has to get to grips with the extreme tides of this region- and use them to his advantage.
Robson is in San Diego, aiming to become only the second angler in the world to have registered the Shark Grand Slam. If he reels in three different species in a single day, he'll have succeeded. But that's easier said than done.
Robson heads for the alligator-infested waters of the Everglades to try for the Bay and Estuary Grand Slam. But first he's training up in the reefs and mangroves of the beautiful Florida Keys.
Robson is trying for his Offshore Grand Slam in Senegal. The waters off this coast provide some of the best fishing in the world - will they help him to Grand Slam glory?
Robson is in Seward going for his Alaskan Grand Slam, where he must catch three species of fish from a set list in a single day. But first he's training in Homer- where the fishing is good- and the halibut are humungous.