My water deck

Monsters:20
3x Warrior of Atlantis (to get Legendary Ocean out)
3x Abyss Soldier (Card used to return unwanted cards on the field)
3x Hydrogreddon (good special summon eff)
2x Amphibious Bugroth MK-13 (works nice if opponent has high defense and i have Legendary Ocean for him to attack directly)
3x Mother Grizzly (helps get Abyss Soldier/Mk-13)
2x Mermaid Knight (nice double attack with Legendary ocean)
2x Snowman Eater (just to get rid of monsters if i use Abyss Soldier eff on a S/T)
2x Penguin Soldier (Same reason as Abyss Soldier)

Spells:13
3x A Ledgenary Ocean
1x MST
1x Heavy Storm
1x Level Limit Area-B
2x Book of Moon
1x Smashing Ground
1x Fissure
3x Salvage

Traps:7
2x Dark Bribe
1x Mirror Force
1x Torrential Tribute
3x Royal Decree

S/T is obvious reasons.

-2 dark bribe that card is so much fail i don't know where to begin only time you should use it is counter fairy deck where it becomes a +1 to you as well sooooooooo ya bad card is bad
-3 royal decree you have 7 traps and 3 decrees much better 7 trap line ups than this yours is just bad.
-1 fissure no need

+2 bottomless trap hole
+1 Solemn judgment
+1 gravity bind if your going for a lvl 3 type of water deck from legendary ocean well ya this should be there as well.
+1 call of the haunted
+1 shrink good for helping your low attack monsters over bigger ones

-2 Bribe
-3 Decree
- Fissure, you already have enough monster removal with bounce effects

+ Call of the Haunted
+1 Shrink, great protection against stronger monsters
+1 Gravity Bind, you have the monsters to use it and be effective
+1 Lightning Vortex, can get rid of a pesky swarm
+1 Terraforming, those times when you need LO and dont have it or can be dumped with effects or costs if you already have LO active
+ Giant Trunade, for when you want to clean your opponents back row for a turn without losing your own

Updated list:

Monsters:18
3x Warrior of Atlantis
3x Abyss Soldier
3x Hydrogeddon
2x Amphibious Bugroth MK-13
3x Mother Grizzly
3x Snowman Eater
1x Penguin Soldier

Spells:13
3x A Legendary Ocean
1x MST
1x Heavy Storm
1x Level Limit-Area B
2x Book of Moon
1x Smashing Ground
1x Salvage
2x Shrink
1x Giant Trunade

Traps:9
1x Call of the Haunted
1x Solemn Judgment
1x Mirror Force
1x Torrential Tribute
1x Gravity Bind
2x Bottomless Trap Hole
2x Dark Bribe

sorry guys this was suppose to be under my name but my bro for got to logout