I know, I know. The admiral is crazy. This works for every fish by the way. It's a game mechanics exploit that works combining two techniques from two people.

First, turn mouse acceleration on and up to 100, so you can wiggle the line back and forth, opposing the fishing and making him move.

Next stand far back away from the shore and cast deep into the water. You have to stand FAR back, well away from the water. The game will automatically bring the admiral close to shore.

Once you hook the admiral, just reel him in and wait for him to come close to the shore or in an exploited manner, he will sometimes come onto the ground.

Once you see he is close or on the ground, just SPRINT UP quickly and the game will automatically register him for a catch.

Yes the admiral is bugged and Ubisoft never fixed it. You can spend hours never catching him and he will even break the line when it is yellow. It is bugged and makes no sense.

But do what I have put down here and you should be able to spring up and eventually get him. You have to do it several times, but I got him on shore in about a minute after spending so much wasted time with the quest bug where he does not tire.

Also, the admiral does not show up as the "admiral." It shows up as "Russian Sturgeon."

OK, you are welcome.