Shipwreck Cove

Shipwreck Cove enters the battlefield tapped.
{t}: Add {u} or {b}
{t}, Sacrifice Shipwreck Cove: Target creature you control gets -1/+1 or +1/-1 until end of turn.
"The sun is glittering in the water and we're expected to reach port before the end of the week."
-Last entrance, Unknown sailors logbook