Successful fly fishers have an understanding of a fish's structure, senses and behavior. This understanding helps them to know when and where to catch more and bigger fish. To exemplify, rainbow trout are most active (feed) in water between 55° - 60° F, while brown trout are most active in water between 60° - 65° F. The "cold blooded" brook trout prefers 52° - 56° F. With this knowledge, one is more likely to fish during the extreme ends of the day if these temperatures are most common in the early morning and the late evenings. This would be an important consideration in the warmer summer months when fish are likely to become lethargic in warmer mid-day waters.

Also consider that fish instinctively avoid bright, clear, open water. This is because shade offers both protective cover from over head predators and an ambush spot. Shade should be an important consideration when you are pursuing fish. There are many ways to exploit shade as you fly fish. Shade provided by over hanging trees and brush, standing timber, suspending logs, edges of weed lines, undercut banks and rocks will hold more fish. If fishing a large boulder with equal current on both sides, fish will be on the shaded side. If practical, fish the shaded side of a stream.

SHADE ATTRACTS FISH AS DO ROCKS

And one more consideration: successful anglers know that fishing often becomes poor after a front moves through bringing high barometric pressure. This "high" brings sunny bright days. Conversely, an approaching front of low pressure brings low levels of light associated with good fishing. Rainy days are known to produce some of the best fishing. Possibly because a fishes highly developed eye lacks eyelids, less sensitive, low light conditions are more inviting. Do fish feed actively because of low light conditions or because of an approaching front resulting in a drop in atmospheric pressure? Either way, this understanding will help you know when is the best time to catch fish, especially big fish.

For many a fly fisher, it's not the battle that excites us, but solving all the problems so the quarry will accept our offering. This section will help you understand one of the biggest questions in fly fishing; why fish take some offering while refusing others?