Without a script that works decent right now, and with the pain of the High Seas booster making the old fish not stack anymore... I have taken a different approach on training another fisher. This may work for you, it may not. It works for me pretty fast until about 85.0, just thought I'd share. I train it on another pc, so it doesn't interfere with my other extra curricular activities.
1) I started with 30 or so fishing trained from a fisher, located near docks.
2) Get a fishing pole (insured) and a cheapo LRC suit (insured)
3) Get a "Crystal Ball of Knowledge" from a vendor or do the easy Quest described here
http://www.uoguide.com/A_Mystic%27s_Journey4) Make sure there isn't anything in your backpack that you don't want to lose, (The crystal ball is blessed so you wont lose that.) Because when I fill up full of fish, I just poison and fireball myself so I don't have to unload fish. Make sure suit is insured and fishing pole is too or it will just make you dig through tons of fish, or have to waste time getting another. The healers are just north west of where I will be fishing anyhow.
5) get UOloop.exe , you can get it many places, google it.
6) Make a UO macro for:
Last object
wait for target
target last
-set your macro key to one that can be used with uoloop, and set delay 8000
7) Mosey on down to Buc's Den Docks
9) With the crystal ball activated, it will tell you when gains are "too easy" "easy" "optimal" "difficult" and so forth. You will want to start close to shore on the docks. Where the crystal ball tells you "fishing difficulty: optimal". As you fish there at an "optimal" location, it will become "easy" once you gain enough skill. Just stop loop, and refish further to the east, away from shore a couple tiles, until it tells you it's "optimal" again. You will gain when "fish aren't biting" also so just stay put until you are filled full of fish or the ball says "fishing difficulty: easy". Run to the west, kill your character, res at healers that are right there... then go back and continue fishing. It gives you about an hour or more until you fill up. Once you have reached 85 skill, you will just have to gain when ball says "easy"
This may seem like a bogus way for some of you, but it gets 'r done!
Hope this can be useful to someone. I have gm'd 2 chars here like this with little effort.