(Drowned Karst isn't a spell.)
Drowned Karst enters the battlefield tapped unless you control an enchantment.
, : Tap target artifact with converted mana cost X or less.
: Add or to your mana pool.
Sacrifice Drowned Karst: Add or to your mana pool.
, 
: Tap target artifact with converted mana cost X or less.: Add 
or 
to your mana pool. or to your mana pool.
