The Hardest Fish To Catch In The World Sailfish. Sailfish are a gorgeous fish which are typically found in tropical and subtropical waters that are deeper than 9 metres. ... Giant Trevally. The Giant Trevally, or GT as it is also called, is one tough fish. ... Swordfish. ... Yellowfin Tuna. ... Atlantic Salmon. ... Dorado. ... Wahoo. ... Barracuda. More items... Sep 9, 2017