Both fly fishing and casting can be practiced. You will be guided by a French qualified guide accompanied by a local guide in some situations such as fishing canoes if the experience tempts you. Most of the fishing will be done by wading from the edge, and an introduction to fly fishing is possible for not experienced in this technique. The Rio Simpson is known for being a paradise for dry fly fishing. Streamers are not to be neglected for some other areas where trophy fish await you.
The best fishing season is from December to the end of March, which corresponds to spring and summer in the southern hemisphere. It is generally very easy to acclimate from the cold winter of Europe to the mild summer climate in Patagonia. The weather can be quite changeable, rain gear must be part of your equipment.
This is the only thing you will need to book yourself. There are not many offers, but Air France (from Paris CDG to Santiago) and LATAM (from Santiagio to Balmaceda, 2 hours) are the preferred companies. Ask your bank to know precisely the repatriation insurance that your credit card gives you. Concerning the currency, you will find Chilean pesos in the airports (1 € = + / - 750 PCL). On site, you can easily use your credit card. Generally, it costs 1000 € the return trip.