Never been a fan of fishing in a game, but will certainly give it a go if the system implemented is engaging. I've Been reading Nepheles posts for the past 6 years, and find myself in agreement with him more often than not. Can't wait to see what he comes up with... especially that underwater fishing.
If you are interested in fishing check out this old thread for ideas proposed regarding fishing...
https://seforums.pantheonmmo.com/content/forums/topic/2873/fishing