This spell disrupts an area of water, making it rougher and choppier. Swimming checks and other checks made by vessels or creatures in the area of effect take a -2 penalty. This is in addition to any other bonuses or penalties in effect due to the nature of the water.
Concentration checks (for spellcasting, etc) may now be required for people aboard ships and in the water, or if they were already required, have a -2 penalty.
Note that the surface of a body of water blocks line of effect, so a caster casting from above can only target a point on the surface. Casters who are underwater may pick any spot within range that they can see.
This spell has no effect on a body of water that is less than 40 feet in every dimension, or less than 5 feet in any dimension.
Scattercalm counters and dispels Scatterwave.
Material component: A handful of sand, tossed towards the center of the emanating spread.