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 drag. For displacement hulls, this represents the theoretical maximum speed.

2. How Does the Calculator Work?

The calculator uses the Hull Speed formula:

Where:

• \( LWL \) — Waterline length in feet
• 1.34 — Empirical coefficient for displacement hulls

Explanation: The formula estimates the speed at which a displacement hull's wave resistance increases dramatically.

3. Importance of Hull Speed Calculation

Details: Knowing a vessel's hull speed helps in design, performance prediction, and fuel efficiency planning. Exceeding hull speed requires exponentially more power.

4. Using the Calculator

Tips: Enter the vessel's waterline length 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. Planing hulls can exceed hull speed by rising over their bow wave.

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 this calculation?
A: It provides a theoretical maximum for displacement hulls. Actual performance may vary based on hull shape and other factors.

Q4: Why is the coefficient 1.34?
A: This empirical value accounts for the relationship between wave length and speed in water, derived from observations of ship performance.

Q5: Can I use this for sailboats?
A: Yes, it's particularly relevant for traditional sailboats with displacement hulls.