Fish will be viable once Rise of the Duelists card hits the market (TCG is still missing Number F0: Utopic Future Dragon tho). Combo is kinda consistent, because its only
Deadreef+any lv4. So we play 3 Deadreef (dumps "big fish"), 3 Beautunaful Princess + 1 One for One, 2-3 Summoner Monk (searches Deadreef and fulfilling the combo but needs spell in hand), therefore we play roughly 9 Deadreef and the rest is just lv4 water extender.
The combo is we summon Dugares (on extra zone) with Deadreef (after sending big fish) + any lv4, use Dugares revive big fish, use big fish discard 1, ss 4 fishes from deck (preferably every copy of Deadreef in our deck as it provides us draw from GY), make Bahamut Shark ss Toadally, make Gallant Granite search Adaman Researcher (or Nibiru if we draw Researcher), ss Researcher, make F0 with Gallant + Bahamut, make Halqifibrax with Researcher + Dugares, ss O-Lion, make Crocodragon with O-Lion + big fish, use Crocodragon draw and chain O-Lion ss lv3 wind machine token. Now you can use Deadreef draw from GY, making us draw 2 in total from our combo.
On opponent's main phase, we can banish Halqifibrax for any synchro tuner (can be anything, depends on you) while having the lv3 wind machine token as the non-tuner for synchro summoning during your opponent's turn. Some synchro tuner can be used during your opponent's battle phase (like Crystron Quandax).
Expected board:
Replay:
https://bit.ly/3bwIc9o (you can replace Dragite with any synchro tuner play)
Pros: Good consistency, multiple negations and disruptions, able to run Deepsea Minstrel to see and snipe opponent's hand, can run bunch of handtraps.
Cons: 2 cards combo, follow up play aint too good, Dugares effect skips your next main phase 1, Beautunaful Princess misses timing if summoned with White Mirror.
Cards to think of: Silent Angler (good lv4 water extender but conflicts with Researcher), other sharks (most of it aint too good), other synchro plays (I put the example on side deck).