The Blessing of Deep Sashelas
The blessing of Deep Sashelas imparts the benefits of the water breathing spell upon the blessed individual (and only that individual).
This blessing takes the form of a mark upon the bearer of the blessing in the shape of a blue dolphin-form where their neck meets their shoulder, on the side of their predominant hand.
The blessing of Deep Sashelas is granted to those who serve the Elven god of the seas. Those who bear the mark imparted by the blessing are recognized as one favored by Deep Sashelas.
The benefits of a blessing are retained forever, or until the blessing is taken away by the god who granted it. Unlike a magic item, a blessing can’t be suppressed by an anti magic field or similar effect.