THE BEACH SURF ZONE TERMINOLOGY
Notes:
- This is an idealized view of the surf zone.
- The Beach - the site of amphibious operations. It extends from the surf zone, where waves are formed, to the tidal high water mark and beyond.
- Surf Zone - the area from the outermost breakers to the limit of wave uprush on the beach face. Surf Zone characteristics will change with changes in tides and weather.
- Surf can be divided into two categories determined by how they are formed: 1) Surf caused by local wind generated waves. Characterized by short, irregular crests, spilling breakers, and a generally confused aspect. 2) Surf caused by swells from a distant wind area. Characterized by regular crests, plunging breakers, and long lines of foam.
- Sandbars - potential hazard as an underwater obstruction, may make the assault beach inaccessible for hours at a time during low tide. Frequently, more than one sandbar exists, seriously impeding landing craft.
- Wave Refraction - can have a major impact on the landing craft in the boat lanes. As the angle of the surf changes as it enters shallower water, it will strike the craft at a different angle.
- Tides - the change of tide may change the whole character of the beach face of the entire surf / breaker zone. While predictable, it may be the critical factor affecting the operation. Currents can also have a major effect on assault craft.