Echolocation

The caster produced a low sound and imbues magical energy into the soundwaves. The vibrations spread out in a 90ft radius sphere around the caster, return to the caster, and repeat this loop for the duration of the spell up to 1 hour. The effect stays centered on and moves with the caster. 

While this sonar field is up, the caster detects the presence and relative size of any creature within the radius. The sound spreads around corners and reveals the location of invisible or hidden creatures. The caster also learns the layout of the terrain within the radius. 

The detection effect can penetrate 1ft of stone, 5ft of wood. if used underwater, the radius is extended by 30ft.