Classification parameters

Tube shape indicates the degree of upthrust, which is roughly proportional to the volume of water being thrown over with the lip. The geometry of tube shape can be represented as a ratio between length and width, such that a perfectly cyllindrical vortex has a length to width ratio of 1:1, while the classic almond shaped tube is nearer 3:1. When 'width' exceeds 'length', the tube is typically described as "square".

Tube shape defined by length to width ratio:

• Square: <1:1
• Round: 1-2:1
• Almond: >2:1

The angle of the peel line reflects the speed of the tube. A fast, "down the line" tube has a peel line with a smaller angle than a slower, "bowly" tube.

Tube speed defined by angle of peel line:

• Fast: 30°
• Medium: 45°
• Slow: 60°