9th level Conjuration
Classes: Sorcerer, Wizard
Domains: Water
Components: V, S
Casting Time: Standard
Range: 1000 ft
Effect: 10-ft.-deep wave 10 ft. wide/level and 2 ft. tall/level
Duration: 5 rounds
Spell Resistance: No
Description: You create a massive wave of water that then moves in a straight line across water or land. You select the direction the wave travels (which must be perpendicular to its width), but once set in motion, the wave cannot change course. Over the surface of open water, the wave travels at a speed of 60 feet per round. On land or underwater, the wave travels at a speed of 30 feet per round.
Creatures struck by a tsunami take 8d6 points of bludgeoning damage (a Constitution save halves this damage). In addition, those struck by the wave must make a Strength saving throw at disadvantage or be knocked prone and carried along by the wave. A creature carried along by a tsunami can attempt another Strength saving throw as a standard action on its turn to escape the pull of the wave. If a creature fails to escape, it takes another 6d6 points of bludgeoning damage (Constitution saving throw for half) and continues being carried along.
Objects struck by a tsunami are swept up if they are Huge or smaller and are carried along by the wave, deposited in a pile at the end of the wave's journey. Gargantuan or larger objects, as well as structures or objects firmly attached to the ground, take 8d6 points of bludgeoning damage when a tsunami passes through its space. If this is enough to destroy the object or structure, the remains are carried along by the wave. Hardness does not reduce this damage, nor is it halved as damage dealt to objects normally is.
A creature with freedom of movement can't be carried along by a tsunami but still takes damage from it. A solid barrier that is taller than the tsunami that is not destroyed by the wave stops that portion of the wave from continuing onward, leaving a gap in the wave as the rest of it continues forward.