Low tide is a term used to describe the lowest level of the tide in a given area. It is caused by the gravitational pull of the moon and sun on the Earth's oceans. The two most common types of low tides are EBB and NEAP. EBB is a three letter word that refers to the outgoing tide, when the water level is at its lowest. NEAP is a four letter word that refers to the incoming tide, when the water level is at its highest.