Deep Sashelas (DEEP SA-sheh-lahs) is the Lord of the Undersea and the patron of sea elves, whom he created long ago by modifying Corellon's land-bound creations. Sashelas is a powerfully creative Power who is forever changing the environments below the sea, creating islands and reefs by altering continental rifts, tinkering with undersea volcanoes, and the like. He is also said to create the deep undersea caverns that the sea elves can use for air-breathing when they wish. Sashelas is known as the Knowledgeable One, for he provides advice as to where food can be found or the enemies are hidden. The sea elves also claim that Deep Sashelas is the author of the Chambeeleon, a resplendent spell tome held in the royal vaults of Thunderfoam an age ago but since lost. Followers of other aquatic gods make similar claims.

The Lord of the Undersea opposes the machinations of all evil powers of the seas, including Abyssal lords such as Demogorgan and Dagon, as well as those whose followers long ago retreated to the Underdark, such as Blibdoolpoolp. Sashelas has a special enmity for Sekolah the Great Shark, the sahuagin patron, and for Panzuriel the Enslaver, a dark Power worshiped by Kaken and other sentient, evil denizens of the ocean depths. The Lord of the Undersea helped banish and weaken Panzuriel long ago. Sashelas respects Panzuriel's growing power, and the Lord of the Undersea considers carefully what steps can be taken to restrain and bind that evil power of the sea bed.

Swim the great currents and the shallow seas. Exult in the ever-changing beauty and life of the bounteous Undersea. Revel in the joy of creation and increase its myriad aspects. Seek not to hold that which is ever-changing, but instead love the change itself. Seek out fellow swimmers who honor the ways of the Lord of the Undersea, and ally with them against those who see only the darkness of the deeps. Follow the way of the dolphin. Promote the use of the seas by all reasonable folk for all time to come; fight those who would hoard its riches or pollute its depths.

The clergy of Deep Sashelas are more organized than most elven churches because of their role as mediators and befrienders of non-aquatic races. Clerics interact regularly with dolphins who inhabit the region surrounding their home communities, and senior clerics are almost always accompanied by their dolphin companions. Sashelan clerics establish and maintain contacts with land-dwelling elves, if feasible. As a result of their extensive networks of contacts, Sashelas's clerics have prevented many sahuagin incursions from succeeding, gaining the latter's undying hatred. Clerics also conduct ritual shark hunts and attack sahuagin communities.