Requires

Saw in Half must be in hand. Sacrifice must be in hand, or in the graveyard. Shipwreck Dowser must be on the battlefield. Mana needed:

Steps

1. Cast Saw in Half by paying , destroying Shipwreck Dowser and creating two token copies of it with base power equal to half the destroyed creature's power and base toughness equal to half the destroyed creature's toughness, rounding up each time.
2. The two Shipwreck Dowser tokens enter the battlefield, returning Sacrifice, if applicable, and Saw in Half from your graveyard to your hand.
3. Cast Sacrifice by paying and sacrificing a Shipwreck Dowser token, adding .
4. Repeat.
5. Once you have infinite mana, you may instead return any other instant or sorcery that can be cast using only black mana in place of Sacrifice using the Shipwreck Dowser tokens to get infinite casts of those instants and/or sorceries.

Results