I love this deck so deeply, thanks a lot for sharing it :)

On the version im building, i've put a lot more counterspells (3 mana ones), which are much easier to play and also really efficient in commander, imo.

For the ramp, why not Gauntlet of Power ? Maybe i missed the part where you removed it for a good reason, which i guess could be that you dont have only basic lands, but if you also play Quicksilver Fountain you become a hate genrator above everything you can imagine _

And since it's a blue ramp, i treated myself by putting some sphinx as well : Consecrated Sphinx and Sphinx of Magosi are extremely powerful in most of situations ;) (i replaced the elementals)

Memnarch is in my maybeboard, the huge generation of mana really put potential on this guy, it could even be an alternative general.

Anyways, great concept, i enjoyed all the playtests i've made, and also enjoyed modifying it to fit my preferences ! :)

I also tried something that is not quiet in the "theme" of the deck, meaning it's not fishy-bouncy, but that is still terrifyingly strong : the Mindshrieker. This guy can litteraly obliterate the opponent if it' not taken seriously, especially in a deck that generates so much mana.

Deadeye Navigator fits the theme and combos nicely with Great Whale for infinite land untaps. Imagine slamming the whale down repeatedly going "WHOOOSH! WHOOOSH! WHOOOSH! WHOOOSH!"

Also, blinking is a great defense against any targeted spell since it effectively counters them.

I avoided Deadeye Navigator in the past, but since I want this deck to do stupid things sometimes I'm now considering it. Thanks Moshanyana!

You're summoning enormous sea monsters and controlling the waves? Well, surely there would be some Flooded Shorelines. Which fit the theme of both bounce and the flavor.

Grozoth is a big dude. He's also a Leviathan that helps you find Inkwell Leviathan and Breaching Leviathan. If you add Deep-Sea Kraken then he could find him as well. Clone Legion and Denying Wind are also 9 CMC blue spells that you could consider but I wouldn't recommend all of them, obviously. That's a lot. Although Clone Legion does state "target player." Meaning you can just target yourself to double the number of sea monsters on your board.

Master of Waves is not a seabeast and does not bounce but I feel that his name makes fairly flavorful and consistent with the rest of the deck. He also synergizes well with all of the blue symbols your permanents have.

These recommendations were based on flavor first and power level second. So, if you don't think they're good enough, I get it.