For the fishing achievement you are supposed to find the hidden treasure. Obviously I will probably never achieve this because it seems impossible but I am just curious what actually is the hidden treasure?

The only person I've ever heard mention winning it is no longer on the site and at the time he mentioned it, he didn't say anything about what the treasure was.

I checked SubetaLodge for any item specific to fishing, and the only things listed are the regular prizes. I checked the item directory and found several time periods where they added fish and fishing gear, but again found nothing unique that could be a specific item prize for fishing.

So based on all that, my guess is there is no special item. The "hidden treasure" is likely composed of some value of sP and/or rare/super rare items (generic, or maybe with a fishing/water/sea type of keyword).

Thank you! It is so odd to me that it is so hard to win with it being an achievement.

There are several other nearly impossible to win achievements - and I'm not talking about absurdly expensive or ridiculously tedious ones either. The 3 hustler ones spring to mind (Amulet of Neutrality, Light Sword of Justice, Dark Staff of Chaos) and Perfect Game (Win a game of Reflection without any wrong guesses).

I've been here 15,5 years and have played the hustler game nearly every day of those years and have not gotten even 1 of them. I play Reflection multiple times a day and I don't think I've ever done better than get the first 2 tiles right.

I know I really wish they could make them easier. I know at one point they said they were going to make the Hustler ones easier but it did not seem to make much of a difference.

Yeah, I'm not sure if they made the fishing one easier or not. Originally you had to hit the exact pixel. We were talking about this on a thread, and Keith popped in to confirm that it really was a single pixel. He looked at how many times it was won and agreed that it was too hard and said he would make it 5x5 (still tiny, but a little more possible). But there was never any confirmation that he actually got around to doing it.