Fly fishing is a fun and relaxing activity. There is quite a number of equipment you need to properly consider in order to land a trout and one among the more important ones is the hook. Fishing hooks follow a numbering system. A size 1 hook is the mid-point of the size range. As the hook gets smaller, the size number increases. So a size 2 is smaller than a size 1 and so on. Any hook larger than 1 is indicated with a slash followed by a zero. So a size 2/0 is bigger than a size 1, etc. Currently the smallest size available is a 32 hook and the biggest is a 19/0 hook.
1. Consider the size of the trout.
The basic rule is that the bigger the fish the bigger the hook. A big fish has a big mouth (and trout can really open their mouths wide) so a big hook can more effectively puncture and latch on. A big fish is also heavy so a big hook is needed to handle the weight. Use a hook that's too small and the trout might just easily escape. Use a hook that's too big and the trout might not bite. There isn't an exact way of matching fish size with hook size. This is really up to the angler's judgment. It would be easier if you have an idea of the average size of trout in the area you plan to do some fly fishing. Rivers, streams and lakes usually have pan-sized trout and most fly fishermen recommend hook sizes ranging from 10 to 14. If you're going after seawater trout and will do some fly fishing in the ocean, bigger hooks are necessary. If you're not certain about how big or small the trout are in the area you've chosen, it would be more prudent to bring along several hooks of various sizes.
2. Consider the kind of fly you're using.
A fly (in fly fishing) is an imitation of an insect that will supposedly attract the trout. The size, color and shape of the fly are also instrumental in getting the trout to bite. So it's equally important to combine the right fly with the right size of hook. Small trout will pass by a fly that's too large no matter how colorful or properly shaped they are. These fish can be pretty clever and a fly that looks good to you doesn't necessarily look tasty on the water to a trout.
Choosing the right sized hook when fly fishing for trout is really a matter of taking into account the size of the trout and the kind of fly you'll be using. The right combination of fly and hook coupled with a correct estimate of the trout's size in the chosen fishing area can make your fly fishing endeavors more successful.