1. What is Hull Speed?

Hull speed is the speed at which the wavelength of a vessel's bow wave equals the waterline length, creating increased resistance and making it inefficient to go faster without expending significantly more power.

2. How Does the Calculator Work?

The calculator uses the hull speed formula:

Where:

• \( LWL \) — Length at waterline in feet
• 1.34 — Empirical coefficient for displacement hulls

Explanation: The formula estimates the maximum efficient speed of a displacement hull vessel based on its waterline length.

3. Importance of Hull Speed Calculation

Details: Knowing a boat's hull speed helps in understanding its performance characteristics, fuel efficiency, and power requirements.

4. Using the Calculator

Tips: Enter the vessel's length at waterline in feet. The value must be greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Can boats exceed hull speed?
A: Yes, but it requires significantly more power and is generally inefficient for displacement hulls. Planing hulls can exceed hull speed by rising up on top of the water.

Q2: Does hull speed apply to all boats?
A: No, it primarily applies to displacement hulls. Planing hulls and semi-displacement hulls can exceed this speed.

Q3: How accurate is the hull speed formula?
A: It provides a good estimate for traditional displacement hulls, but actual performance may vary based on hull shape and other factors.

Q4: What affects a boat's hull speed?
A: Primarily the waterline length, but also hull shape, displacement, and wave-making characteristics.

Q5: Why is the coefficient 1.34?
A: This is an empirical value derived from observations of wave-making resistance in displacement hulls.