Winged Boots

Equipped creature has flying and ward {4}. (Whenever equipped creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {4}.)
Equip {1}

Buried Treasure

{T}, Sacrifice Buried Treasure: Add one mana of any color.
{5}, Exile Buried Treasure from your graveyard: Discover 5. Activate only as a sorcery. (Exile cards from the top of your library until you exile a nonland card with mana value 5 or less. Cast it without paying its mana cost or put it into your hand. Put the rest on the bottom in a random order.)

Zephyr Boots

Equipped creature has flying.
Whenever equipped creature deals combat damage to a player, draw a card, then discard a card.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Coral Eel

Dwarven Sea Clan

{T}: Choose target attacking or blocking creature whose controller controls an Island. Dwarven Sea Clan deals 2 damage to that creature at end of combat. Activate only before the end of combat step.

Treasure Chest

{4}, Sacrifice Treasure Chest: Roll a d20.
1 | Trapped! — You lose 3 life.
2—9 | Create five Treasure tokens.
10—19 | You gain 3 life and draw three cards.
20 | Search your library for a card. If it's an artifact card, you may put it onto the battlefield. Otherwise, put that card into your hand. Then shuffle.

Coastal Tower

Coastal Tower enters tapped.
{T}: Add {W} or {U}.

Sol Ring

Wormfang Behemoth

When Wormfang Behemoth enters, exile all cards from your hand.
When Wormfang Behemoth leaves the battlefield, return the exiled cards to their owner's hand.

Lavaglide Pathway

Riverglide Pathway

Riverglide Pathway // Lavaglide Pathway

Colossal Skyturtle

Flying, ward {2}
Channel — {2}{G}, Discard Colossal Skyturtle: Return target card from your graveyard to your hand.
Channel — {1}{U}, Discard Colossal Skyturtle: Return target creature to its owner's hand.

Volcanic Island

Mikokoro, Center of the Sea

{T}: Add {C}.
{2}, {T}: Each player draws a card.

Flooded Grove

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

River of Tears

{T}: Add {U}. If you played a land this turn, add {B} instead.

Bronze Walrus

When Bronze Walrus enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)
{T}: Add one mana of any color.

Quagmire Lamprey

Whenever Quagmire Lamprey becomes blocked by a creature, put a -1/-1 counter on that creature.

Stormcarved Coast

Stormcarved Coast enters tapped unless you control two or more other lands.
{T}: Add {U} or {R}.

River Delta

River Delta doesn't untap during your untap step if it has a depletion counter on it.
At the beginning of your upkeep, remove a depletion counter from River Delta.
{T}: Add {U} or {B}. Put a depletion counter on River Delta.

Sleep with the Fishes

Enchant creature
When Sleep with the Fishes enters, tap enchanted creature and you create a 1/1 blue Fish creature token with "This creature can't be blocked."
Enchanted creature doesn't untap during its controller's untap step.

Soaring Seacliff

Soaring Seacliff enters tapped.
When Soaring Seacliff enters, target creature gains flying until end of turn.
{T}: Add {U}.

Sky-Eel School

Flying
When Sky-Eel School enters, draw a card, then discard a card.

Treasure Hunt

Reveal cards from the top of your library until you reveal a nonland card, then put all cards revealed this way into your hand.

Scuttlegator

Defender
{6}{G/U}{G/U}: Adapt 3. (If this creature has no +1/+1 counters on it, put three +1/+1 counters on it.)
As long as Scuttlegator has a +1/+1 counter on it, it can attack as though it didn't have defender.

Lavaspur Boots

Equipped creature gets +1/+0 and has haste and ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)
Equip {1}

Octoprophet

When Octoprophet enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Ancient Carp

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.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Water Elemental

Moat Piranhas

Old Man of the Sea

You may choose not to untap Old Man of the Sea during your untap step.
{T}: Gain control of target creature with power less than or equal to Old Man of the Sea's power for as long as Old Man of the Sea remains tapped and that creature's power remains less than or equal to Old Man of the Sea's power.

Devouring Deep

Islandwalk (This creature can't be blocked as long as defending player controls an Island.)

Island

Darkwater Catacombs

Sea Troll

{U}: Regenerate Sea Troll. Activate only if Sea Troll blocked or was blocked by a blue creature this turn.

Sharktocrab

{2}{G}{U}: Adapt 1. (If this creature has no +1/+1 counters on it, put a +1/+1 counter on it.)
Whenever one or more +1/+1 counters are put on Sharktocrab, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.

Water Wurm

Water Wurm gets +0/+1 as long as an opponent controls an Island.

Riptide Crab

Vigilance
When Riptide Crab dies, draw a card.

Stinging Lionfish

Whenever you cast your first spell during each opponent's turn, you may tap or untap target nonland permanent.

Marauding Brinefang

Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Islandcycling {2} ({2}, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.)

Killer Whale

{U}: Killer Whale gains flying until end of turn.

Fishing Pole

Equipped creature has "{1}, {T}, Tap Fishing Pole: Put a bait counter on Fishing Pole."
Whenever equipped creature becomes untapped, remove a bait counter from this Equipment. If you do, create a 1/1 blue Fish creature token.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Cold-Water Snapper

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Giant Octopus

Sea God's Scorn

Return up to three target creatures and/or enchantments to their owners' hands.

Puffer Extract

{X}, {T}: Target creature you control gets +X/+X until end of turn. Destroy it at the beginning of the next end step.

Meandering River

Meandering River enters tapped.
{T}: Add {W} or {U}.

Sea-Dasher Octopus

Mutate {1}{U} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Flash
Whenever this creature deals combat damage to a player, draw a card.

Swiftwater Cliffs

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {U} or {R}.

Seafloor Debris

Seafloor Debris enters tapped.
{T}: Add {U}.
{T}, Sacrifice Seafloor Debris: Add one mana of any color.

Hermitic Nautilus

Vigilance
{1}{U}: Hermitic Nautilus gets +3/-3 until end of turn.

Giant Oyster

You may choose not to untap Giant Oyster during your untap step.
{T}: For as long as Giant Oyster remains tapped, target tapped creature doesn't untap during its controller's untap step, and at the beginning of each of your draw steps, put a -1/-1 counter on that creature. When Giant Oyster leaves the battlefield or becomes untapped, remove all -1/-1 counters from the creature.

Wall of Kelp

Defender (This creature can't attack.)
{U}{U}, {T}: Create a 0/1 blue Plant Wall creature token with defender named Kelp.

Man-o'-War

When Man-o'-War enters, return target creature to its owner's hand.

Waterwhirl

Return up to two target creatures to their owners' hands.

Tropical Island

Sea Gate Wreckage

{T}: Add {C}. ({C} represents colorless mana.)
{2}{C}, {T}: Draw a card. Activate only if you have no cards in hand.

School of Piranha

At the beginning of your upkeep, sacrifice School of Piranha unless you pay {1}{U}.

Underground Sea

Waterveil Cavern

{T}: Add {C}.
{T}: Add {U} or {B}. Waterveil Cavern doesn't untap during your next untap step.

Sinister Starfish

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Sea Monster

Sea Monster can't attack unless defending player controls an Island.

Deep Water

{U}: Until end of turn, if you tap a land you control for mana, it produces {U} instead of any other type.

Wu Warship

Wu Warship can't attack unless defending player controls an Island.

Trailblazer's Boots

Equipped creature has nonbasic landwalk. (It can't be blocked as long as defending player controls a nonbasic land.)
Equip {2}

Walking Sponge

{T}: Target creature loses your choice of flying, first strike, or trample until end of turn.

Sea God's Revenge

Return up to three target creatures your opponents control to their owners' hands. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Volatile Fjord

({T}: Add {U} or {R}.)
Volatile Fjord enters tapped.

Ghost Ship

Molten Tributary

({T}: Add {U} or {R}.)
Molten Tributary enters tapped.

Kapsho Kitefins

Flying
Whenever Kapsho Kitefins or another creature you control enters, tap target creature an opponent controls.

Boots of Speed

Equipped creature gets +1/+0 and has haste.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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

Thallid Soothsayer

Rimewood Falls

({T}: Add {G} or {U}.)
Rimewood Falls enters tapped.

Sigiled Starfish

{T}: Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Waterlogged Grove

{T}, Pay 1 life: Add {G} or {U}.
{1}, {T}, Sacrifice Waterlogged Grove: Draw a card.

Wall of Water

Defender (This creature can't attack.)
{U}: Wall of Water gets +1/+0 until end of turn.

Water Wings

Until end of turn, target creature you control has base power and toughness 4/4 and gains flying and hexproof. (It can't be the target of spells or abilities your opponents control.)

Sea Spirit

{U}: Sea Spirit gets +1/+0 until end of turn.

Floodwaters

Return up to two target creatures to their owners' hands.
Cycling {2} ({2}, Discard this card: Draw a card.)

Seaside Citadel

Seaside Citadel enters tapped.
{T}: Add {G}, {W}, or {U}.

Glowing Anemone

When Glowing Anemone enters, you may return target land to its owner's hand.

Giant Crab

{U}: Giant Crab gains shroud until end of turn. (It can't be the target of spells or abilities.)

Manta Ray

Manta Ray can't attack unless defending player controls an Island.
Manta Ray can't be blocked except by blue creatures.
When you control no Islands, sacrifice Manta Ray.

Mesmerizing Benthid

When Mesmerizing Benthid enters, create two 0/2 blue Illusion creature tokens with "Whenever this creature blocks a creature, that creature doesn't untap during its controller's next untap step."
Mesmerizing Benthid has hexproof as long as you control an Illusion.

Sisay's Ring

Red Herring

Haste
Red Herring attacks each combat if able.
{2}, Sacrifice Red Herring: Draw a card.

Murkwater Pathway

Clearwater Pathway

Clearwater Pathway // Murkwater Pathway

Tangle Kelp

Enchant creature
When Tangle Kelp enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step if it attacked during its controller's last turn.

Yavimaya Coast

{T}: Add {C}.
{T}: Add {G} or {U}. Yavimaya Coast deals 1 damage to you.

Rootwater Depths

{T}: Add {C}.
{T}: Add {U} or {B}. Rootwater Depths doesn't untap during your next untap step.

Horseshoe Crab

Wavebreak Hippocamp

Whenever you cast your first spell during each opponent's turn, draw a card.

Ancient Crab

Sea Serpent

Sea Serpent can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Sea Serpent.

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Surge Mare

Surge Mare can't be blocked by green creatures.
Whenever Surge Mare deals damage to an opponent, you may draw a card. If you do, discard a card.
{1}{U}: Surge Mare gets +2/-2 until end of turn.

Dandân

Dandân can't attack unless defending player controls an Island.
When you control no Islands, sacrifice Dandân.

Idyllic Beachfront

({T}: Add {W} or {U}.)
Idyllic Beachfront enters tapped.

Electric Eel

When Electric Eel enters, it deals 1 damage to you.
{R}{R}: Electric Eel gets +2/+0 until end of turn and deals 1 damage to you.

Omen of the Sea

Flash (You may cast this spell any time you could cast an instant.)
When Omen of the Sea enters, scry 2, then draw a card.
{2}{U}, Sacrifice Omen of the Sea: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Glittering Stockpile

{T}: Add {R}. Put a stash counter on Glittering Stockpile.
{T}, Sacrifice Glittering Stockpile: Add X mana of any one color, where X is the number of stash counters on Glittering Stockpile.

Ominous Seas

Whenever you draw a card, put a foreshadow counter on Ominous Seas.
Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.
Cycling {2} ({2}, Discard this card: Draw a card.)

Crystacean

Flash (You may cast this spell any time you could cast an instant.)