Mimano and Oboro are optional maindeck protection from Choke because they come in untapped and tap for a blue.

I've made budget adjustments to the deck but there's always room for improvement.

Below is a list copied from Jon Patton's GP Omaha 2015 top8.

20 LANDS
14 Island
2 Mutavault
2 Cavern of Souls
1 Minamo, School at Water's Edge
1 Oboro, Palace in the Clouds
27 CREATURES
4 Merrow Reejerey
4 Silvergill Adept
4 Cursecatcher
4 Master of the Pearl Trident
4 Lord of Atlantis
3 Phantasmal Image
2 Kira, Great Glass-Spinner
2 Master of Waves
7 INSTANTS and SORC.
3 Vapor Snag
2 Spell Pierce
2 Echoing Truth
6 OTHER SPELLS
4 Æther Vial
2 Spreading Seas
SIDEBOARD
2 Torpor Orb
2 Spellskite
1 Relic of Progenitus
3 Hurkyl's Recall
3 Chalice of the Void
2 Tidebinder Mage
2 Swan Song