The conversation in the backpack thread made me curious, it would be nice to share our knowledge about the spots that we can net iridium fish at low level, speeding up our gameplay and receiving more energy by catch a iridium/gold chub. I found this one today on the mountain lake, my fishing level was lv0 and I got a gold largemouth bass, then in lv1 I was able to cast on that algae and started to receive iridium to gold catches.
The tip of Arrowhead Island and the island in the middle of the Mountain Lake are two such places. The first one is obvious, the second is where you'd go to try and land the Legend if you had sufficient Fishing skill to get your lure out by that sunken log. Also, off the docks anywhere along the beach or tidal pools are usually pretty good. I'm a fan of Lone Rock, but that's sheer sentimentality.
I've been spending most of yesterday and half of today learning map editing. There is a "fish" map property, but the consensus is that it is not used. Assigning arbitrary values seems to make no difference. You can mark a tile as "Water" and "NoFishing", but they are both pseudo-boolean -- any non-empty value is the same, so those fields can't be used to mark a +25% fishing spot, for instance. It just is or is not eligible for fishing. Point being that we are probably looking at a straightforward distance algorithm; that, as @ShneekeyTheLost suggests, any difference is likely superstition and confirmation bias. Yes, when you are standing on a corner (water on 2 sides) shifting the cast into that row or column makes it a longer cast. So in your example, @WilliamZ, you get extra distance because you shifted the cast to the north and the tile directly north of you is water. Any place you can find that shoreline feature you can get an extra tile. That's what I was doing south of Jodi's that gave me better catches -- standing on the corner directly south of her door, there's water to the west. Shifting the cast west made the distance greater than casting directly south. I have not yet decided whether shifting it sideways while standing on a straight shore makes any difference. (Measured along the hypotenuse is longer than measured along the leg; but does the algorithm care?) Doesn't appear to be much, if any. Can't rule out confirmation bias anyway.
