This list was inspired by an Ula's Temple deck I used to play. It's not a tribal deck in the normal sense because it doesn't focus on one or two creatures types, but its tribal ties are linked to Ula's Temple (Kraken, Leviathan, Octopus and Serpent). In the standard list, it relied heavily on Augury Owl and Sage Owl so I would make the joke it was more Owl Tribal than anything else. The owls being so important to the deck justified them being in this incarnation as well.
I originally wanted a UBG commander since I wanted to add a few of the multicolored creatures of relevance as well such as Simic Sky Swallower and Wrexial, the Risen Deep, but none really fit the flavor and I was pondering about The Mimeoplasm with a deck not really tailored to him just for the sake of casting him and reanimating my sea creatures with bigger bodies than before. Thassa was spoiled, she fit the sea creature theme, she was super cheap and could be cast turn 3 and stay on the field AND her scy ability went well with Ula's Temple so I had to go mono blue from there.


Possible Changes from the list
omenspeaker - scry themed, little utility though
prognostic sphinx - [reserved for another flyer]
Jokulmorder - badass, he's pretty metal. someday I will win with him

Cards I might add
Grozoth
quicksilver fountain - although will draw hate
cards that turn lands into islands, but last longer than until end of turn. Honestly though, with all the cards in blue that care about you and/or your opponents having islands, I feel like blue should have gotten an Island version of Urborg.
Force of Will, because I need good cards to protect my bad ones.
Tolaria West

others
high tide - for theme
All is Dust
karn liberated
jace, the mind sculpter
mana drain/counterspell - far down the road when i decide to become 'that guy'

outs/ins
jn gitaxas / pull from tomorrows
sower of temptation / pearl lake ancient
harbor serpent / slinn voda
devastation tide / crush of tentacles
floodchaser  / elder deep-fiend

Outs > Ins
Darksteel Ingot > Skyclave Relic
Dissipation Field > Spawning Kraken
Treasure Hunt > Fierce Guardianship
Sphinx of Jwar Isle > Brinelin the Moon Kraken

Potential Cuts
Venser, Shaper Savant
Sealock Monster
Colossal Whale
Elder Deep-Fiend
Gomazoa
Guard Gomazoa
Pearl Lake Ancient

Potential Adds
Ominous Seas
Kiora Bests the Sea God
Icebreaker Kraken