Aquitect's Will is a common Kindred Sorcery — Merfolk card from Duel Decks: Merfolk vs. Goblins (DDT), collector number 2. Current market price: $0.35, TCGplayer market prices via Scryfall.
Put a flood counter on target land. That land is an Island in addition to its other types for as long as it has a flood counter on it. If you control a Merfolk, draw a card.