Underground Sea
Land — Island Swamp
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- CMC
- 0
- Mana cost
- Color identity
- BU
- Rarity
- rare
- Set
- Unlimited Edition
- Price
- $1208.94
- EDHREC rank
- #297
Underground Sea enters untapped, taps for blue or black with no drawback, and never asks you to pay a life or wait a turn — it is simply the best dual land available for any deck in its color identity. At over $1,200, Rograkh, Son of Rohgahh // Silas Renn, Seeker Adept lists run it at an 84% rate because the ceiling on a perfect mana base is worth chasing when the deck is built to win.
Best Commanders
Commanders with the highest synergy
Rograkh, Son of Rohgahh // Silas Renn, Seeker Adept
Silas Renn demands both blue and black mana on curve, and the artifact-reanimation engine this pair runs can't afford tapped lands slowing down its early setup — Underground Sea is the cleanest way to have both colors available on turn one.
Tevesh Szat, Doom of Fools // Thrasios, Triton Hero
Tevesh Szat, Doom of Fools // Thrasios, Triton Hero is a cEDH staple built around generating and spending infinite mana, and Underground Sea slots into the optimized mana base that lets the deck execute its lines without color constraints.
Malcolm, Keen-Eyed Navigator // Vial Smasher the Fierce
Malcolm, Keen-Eyed Navigator // Vial Smasher the Fierce runs a Grixis spell-slinging shell that needs blue open for counterspells and black open for interaction on the same turn — Underground Sea covers both without compromise.
Sisay, Weatherlight Captain
Sisay, Weatherlight Captain runs five colors and needs every pip it can find in the early turns; Underground Sea's unconditional blue-black production makes it a reliable piece of a mana base that would otherwise lean too hard on green fixing.
Talion, the Kindly Lord
Talion, the Kindly Lord is a Dimir tempo commander that punishes opponents for playing spells of the chosen value — Underground Sea ensures the deck never stumbles on its two-color requirements when it needs to hold up interaction.
Format Analysis
Where it lives, where it can’t
| Format | Verdict |
|---|---|
| commander | legal |
| legacy | legal |
| modern | not legal |
| pioneer | not legal |
| standard | not legal |
| vintage | legal |
| pauper | not legal |
| oathbreaker | legal |
In Commander, Underground Sea is the gold standard for Dimir and any multicolor deck touching blue and black — no other land produces both colors without a condition attached. Legacy is where Underground Sea also sees serious competitive play, underpinning blue-black control and combo shells that need to function on turn one without any life loss or tempo penalty. Vintage permits it as well, though the sheer density of powerful mana options there makes it one of many rather than the centerpiece. Underground Sea is not legal in Modern, Pioneer, Standard, or Pauper, so outside of Commander and the older eternal formats it simply doesn't exist as an option.
Key Combos
Combo lines featuring this card
Budget Alternatives
Cheaper options that do most of the same work
The closest functional replacement for Underground Sea is Watery Grave, which enters untapped if you pay 2 life — a trivial cost in most games and available for under $5. Sunken Hollow is another option that enters untapped whenever you control two or more basics, though it's unreliable in greedy multicolor mana bases where basics are scarce; between the two, Watery Grave replicates what Underground Sea does in the vast majority of game situations at a fraction of the price.
Price Context
Current price
$1208.94 premium tier
At $1,208.94, Underground Sea sits firmly in the top tier of Magic card prices — this is a Reserved List dual land, and that designation means Wizards has committed to never reprinting it. The price reflects genuine scarcity and sustained demand from Legacy and Commander players alike, and it has historically held value better than almost any other card in the game.
Explore
Sources
Mentioned
- Rograkh, Son of Rohgahh // Silas Renn, Seeker Adept
- Tevesh Szat, Doom of Fools // Thrasios, Triton Hero
- Malcolm, Keen-Eyed Navigator // Vial Smasher the Fierce
- Sisay, Weatherlight Captain
- Talion, the Kindly Lord
Updated . Data from Scryfall, EDHREC, and Commander Spellbook.