If you also into survival and dumping yourself in the wilderness for a week here and there with nothing except a first aid kit and a knife, then a jetboil is a welcome addition, however jsut for fishing I would say that anything from a local hardware store would suffice, and they're usually not to badly priced, either. One thing I use when im on the river fishing for trout and salmon, is the ration pack heat packs (I acutally made my own 'microwave' thing for cooking meals I had prepared using the ration pack heaters, squeezing as much of the heat out of them as possible. It wasnt even that expensive to make. The reason I went down this route is fires are an outright no-no on my local river, and from speaking to one of the baliffs I'm friendly with down here, we both decided it was a grey area, and I dont fancy upsetting other anglers or seemingly bending the rules. However now that im fishing on lakes and such for course+carp, fires/stove are allowed on the bank generally speaking so I've been looking at getting a standard single-stove gas cooker with the 'deodorant style' butane canisters, its all cheap enough and you dont mind if it gets wet here and there, and with the cost of jetboils, running the risk of water damage + rust is a genuine concern given the price. In my opinion, I think getting the cheap stoves are best suited for fishing on the lakeside as you can easily buy 10 stoves for the price of a single jetboil. Ration pack heaters are also a good options, and are very light to carry, as well as ration packs themselves, or even creating your own ration packs.
Like I said though, if you are going to use is it for other things, like boiling water for drinking and going on expeditions, then a jetboil is a great buy, I wouldnt get one just for fishing alone though.
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