# SURF ZONE

The area between the outermost limit of breakers and the limit of wave uprush.

## Related Terms

### BALANCED RUDDER

A rudder design where the pivot point and the center of its area meet, reducing the effort needed to turn it.

It has about 20% of the rudder area forward of the rudder axis.

### CENTRE OF BUOYANCY

The center of the area of the underwater transverse or longitudinal section of a hull at a particular trim, hence the point at which the force of buoyancy is regarded to be acting vertically upwards.

### PNEUMATIC CONTROL VALVE

A valve in which the force of compressed air against a diaphragm is opposed by the force of a spring to control the area of the opening for a fluid stream.

### PLASMA-ARC CUTTING

Metal cutting by melting a localized area with an arc followed by removal of metal by high-velocity, high-temperature ionized gas.

### PLAN EQUATION

The mathematical statement that horsepower plan/33,000, where p mean effective pressure (pounds per square inch), l length of piston stroke (feet), a net area of piston (square inches), and n number of cycles completed per minute.

### PISTON GAGE SEE FREE-PISTON GAGE. PISTON METER

A variable-area, constanthead fluid-flow meter in which the position of the piston, moved by the buoyant force of the liquid, indicates the flow rate. Also known as piston-type area meter.

### PICTURE ELEMENT

1. That portion, in facsimile, of the subject copy which is seen by the scanner at any instant; it can be considered a square area having dimensions equal to the width of the scanning line. 2. In television, any segment of a scanning line, the dimension of which along the line is exactly equal to the nominal line width; the area which is being explored at any instant in the scanning process. Also known as critical area; elemental area; pixel; recording spot; scanning spot.

### PARISON SWELL

In blow molding, the ratio of the cross-sectional area of the pariso

### PACKING DENSITY

The number of devices or gates per unit area of an integrated circuit. packing ring See piston ring.

### OVERRUN

A cleared area extending beyond the end of a runway.

### Related questions

MarineProHelp 2018 - 2021