Table of Contents #4.7 The operator is able to:
A: Cross waves or wakes... B: by using an appropriate angle of approach and controlling boat speed for the given wake/wave size and frequency.
Understanding the Element
• Improperly crossing waves or boat wakes can cause injury to those on board as well as damage to the boat. Operators must judge wave size and length and react appropriately.
• The term “frequency” refers to rate of a wave but is being used as a measure of wavelength. The actual speed of a wave or frequency of a wave is not as important as the relative speed with which a boat crosses each crest.
• Rate measures the number of crests that pass a given point in a unit of time. Frequency measures the number of
time units between each crest. Each is a function of wave speed. Wavelength is the distance between crests and the greater the wavelength for waves of the same height the more gradual their slope will be and the easier it is for a boat to safely pass through them.
Designing Instruction
• Consider having student boats follow the instructor’s boat in a large figure-8 while gradually increasing speed. The boats all cross each other’s wake, and the students have the boat ahead of them as a reference. This may help build confidence for operating in waves.
• This element teaches the student that the effective distance between waves can be increased by crossing the wave system at an angle (45° is often mentioned in the literature, but this should not be regarded as an absolute). A short steep wave will cause more damage to a boat than a long gradual wave even though the latter may be much higher.
Assessing Performance Level
Successful Performance
Needs
3 2
Improvement
Unacceptable (Unsuccessful) Performance
1 The operator:
Adjusts angle of approach to a wave or series of waves to increase effective distance between waves. Adjusts speed as necessary to avoid damage to equipment and minimize discomfort to passengers when operating in waves. Adjusts speed and angle to waves when operating down swell. Ensures passengers are securely positioned. Adjusts promptly to changing conditions.
The operator:
Adjusts angle of approach to a wave or series of waves to increase effective distance between waves 80- 95% of the time. Uses proper speed 80-95% of the time to avoid damage to equipment and minimize discomfort to passengers. Operates at proper angle to waves and speed when operating down swell 80-95% of the time. Ensures passengers are securely positioned. Adjusts to changing conditions but not promptly.
The operator:
Adjusts angle of approach to a wave or series of waves to minimize effect on boat less than 80% of the time. Approaches waves too fast more than 20% of the time, causing damage to equipment or extreme discomfort to passengers. Does not adjust speed and angle to waves when operating down swell. Broaches or buries the bow. Fails to ensure passengers are securely positioned. Does not adjust to changing conditions.
Proficiency description
This Technical Support Document was produced in part through USCG grant funds to develop National On-Water Skills Standards. 45 ©2022 United States Sailing Association. Facilitated by Think First Serve.
Element
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