Siren Stormtamer

Flying
{U}, Sacrifice Siren Stormtamer: Counter target spell or ability that targets you or a creature you control.

Merchant Raiders

Whenever Merchant Raiders or another Pirate enters the battlefield under your control, tap up to one target creature. That creature doesn't untap during its controller's untap step for as long as you control Merchant Raiders.

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Dreamcaller Siren

Flash
Flying
Dreamcaller Siren can block only creatures with flying.
When Dreamcaller Siren enters the battlefield, if you control another Pirate, tap up to two target nonland permanents.

Ipnu Rivulet

{T}: Add {C}.
{T}, Pay 1 life: Add {U}.
{1}{U}, {T}, Sacrifice a Desert: Target player mills four cards.

Deadeye Rig-Hauler

Raid — When Deadeye Rig-Hauler enters the battlefield, if you attacked this turn, you may return target creature to its owner's hand.

Pirate Ship

Pirate Ship can't attack unless defending player controls an Island.
{T}: Pirate Ship deals 1 damage to any target.
When you control no Islands, sacrifice Pirate Ship.

Island

Command Tower

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

Warkite Marauder

Flying
Whenever Warkite Marauder attacks, target creature defending player controls loses all abilities and has base power and toughness 0/1 until end of turn.

Corsair Captain

When Corsair Captain enters the battlefield, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Other Pirates you control get +1/+1.

Spell Swindle

Counter target spell. Create X Treasure tokens, where X is that spell's mana value. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Lookout's Dispersal

This spell costs {1} less to cast if you control a Pirate.
Counter target spell unless its controller pays {4}.

Storm Fleet Aerialist

Flying
Raid — Storm Fleet Aerialist enters the battlefield with a +1/+1 counter on it if you attacked this turn.

Thriving Isle

Thriving Isle enters the battlefield tapped.
As Thriving Isle enters the battlefield, choose a color other than blue.
{T}: Add {U} or one mana of the chosen color.

Treasure Cove

(Transforms from Treasure Map.)
{T}: Add {C}.
{T}, Sacrifice a Treasure: Draw a card.

Treasure Map

{1}, {T}: Scry 1. Put a landmark counter on Treasure Map. Then if there are three or more landmark counters on it, remove those counters, transform Treasure Map, and create three Treasure tokens. (They're artifacts with "{T}, Sacrifice this artifact: Add one mana of any color.")

Treasure Map // Treasure Cove

Malcolm, Keen-Eyed Navigator

Flying
Whenever one or more Pirates you control deal damage to your opponents, you create a Treasure token for each opponent dealt damage. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Partner (You can have two commanders if both have partner.)

Desert of the Mindful

Desert of the Mindful enters the battlefield tapped.
{T}: Add {U}.
Cycling {1}{U} ({1}{U}, Discard this card: Draw a card.)

Amphin Mutineer

When Amphin Mutineer enters the battlefield, exile up to one target non-Salamander creature. That creature's controller creates a 4/3 blue Salamander Warrior creature token.
Encore {4}{U}{U} ({4}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Departed Deckhand

When Departed Deckhand becomes the target of a spell, sacrifice it.
Departed Deckhand can't be blocked except by Spirits.
{3}{U}: Another target creature you control can't be blocked this turn except by Spirits.

Squidnapper

When Squidnapper enters the battlefield, gain control of target creature an opponent controls until Squidnapper leaves the battlefield or that player pays the ransom.
Ransom — {6} and 2 life

Admiral's Order

Raid — If you attacked this turn, you may pay {U} rather than pay this spell's mana cost.
Counter target spell.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.