Choked Estuary

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

Island

Morphic Pool enters tapped unless you have two or more opponents.
{T}: Add {U} or {B}.

{T}: Add one mana of any color in your commander's color identity.

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

{T}: Add {C}.
{T}: Add {U} or {B}. Activate only if you control a Swamp.

{T}: Add {C}.
{U/B}, {T}: Add {U}{U}, {U}{B}, or {B}{B}.

Shipwreck Marsh enters tapped unless you control two or more other lands.
{T}: Add {U} or {B}.

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

You have no maximum hand size.
{T}: Add {C}.

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.