Important to think about when going fishing
Reel or Fly
The water in the mountains is almost clear as glass. This can make the fish easily scared. Be careful when you move along the shore. Don’t use thicker line than necessary, 0.18-0.20 monofilament is more than good enough or multifilament 0.12-0.17. If you use a brightly-colored multifilament line, it is a good idea to tie on a snell with a more "invisible" monofilament line.
The color of the lure doesn’t have to mean anything–more important is the weight, the presentation, and gait. Fish-like lures are always effective because they are long-casting. In smaller waters, where the range doesn’t mean so much, traditional spoon lures, wobblers, and spinners work well. Adjust the depth that you want to fish with the weight of what you are using. This also decides the speed and gait to a large extent. Another factor that is easy to forget, and which has a lot to do with the length of the cast, is the gram weight of the rod you are using. This information is on the rod just over the reel mount.
If you want to try fly fishing, it is recommended to bring a good selection of dry flies, wet flies, and streamers. Then you are equipped for the vast majority of conditions, and they can change quickly in the mountains. If you are not a dedicated fly fisherman with a fly rod, a casting float and fly will do just as well. Some good flies that you should definitely have in your tackle box are varieties of Streaking Caddies, Zulu Silver and Wolly Bugger.
It must also be mentioned that you must always have two of each in fly or lure. This is to ensure that you are not left without your favorite lure/fly or the one that turns out to work best that day
There is always good fishing weather. This is the only thing with which you need to deal, no matter where you are in the country. So forget biting tables, wind directions, and moon phases. Something you should think about, however, is how the weather affects the fish's positions and movements. There are many variables, and a deeper understanding of this can only be gained through experience. Having said that, you can smile a little extra if the weather shows cloudy skies and wind. If, on the other hand, there is sun from a cloudless sky and little wind, all you have to do is pack the sunscreen and apply it with patience. However, if you are going out fishing on sunny and calm days, look for shade, deeper areas, currents, or go fishing early in the morning and late in the afternoon.
Trout, which is primarily the fish you will find in and around Geilo, thrives best when the water temperature is around 12 C degrees. Everything over or under this doesn’t necessarily mean that the fishing will be any worse, but the trout will generally try to use as little effort as possible to eat.
The season begins with the ice breaking. This varies from year to year, but around May 17th, the ice is usually gone around the center of the village. That said, don’t be surprised if you arrive at a frozen lake. The ice melts late in the mountains, and waters located in the high, alpine areas, like Skorpa and the Hallingskarvet mountains, aren’t ice-free before late July, and sometimes early August. If you are unsure, check with the sports stores so you avoid an unnecessary trip.