The most important part of fishing offshore (key west to key largo) is learning where the Gulfstream starts, as this is often the beginning of the larger fish, especially first thing in the morning. Many boats work the edge on a daily basis, so the fish can become less numerous as the day goes along. Another term you will hear the captains talk about are the Rips. In simple terms, this is where the ocean floor is highly uneven, a fish attractant. Also, look to the sky-air for the birds, as they do help locate the mahi and other seasonal schooling fish. Another winner for fishing is around the floating debris, which are not square grouper. Yes, best are the sargasso weed patches but there is all kinds of branches, logs, boards, and clumps of debris. Fishing these areas can often be the most productive as wahoo and mahi love to swim around the floating stuff. I hope this helps a bit and going out one time with a good guide can show you these tips in practice.