1. What is Hull Speed?

Hull speed is the theoretical maximum speed a displacement hull can achieve without planing. It's determined by the waterline length of the vessel and represents the point where the wavelength of the boat's wake equals the waterline length.

2. How Does the Calculator Work?

The calculator uses the hull speed formula:

Where:

• \( Hull\_speed \) — Theoretical maximum speed in knots
• \( LWL \) — Waterline length in feet
• 1.34 — Empirical coefficient for displacement hulls

Explanation: The formula calculates the speed at which the wavelength of the boat's wake equals the boat's waterline length, creating increased drag.

3. Importance of Hull Speed Calculation

Details: Knowing a boat's hull speed helps in understanding its performance characteristics, fuel efficiency at different speeds, and when designing or selecting a vessel for specific purposes.

4. Using the Calculator

Tips: Enter the waterline length in feet. The value must be greater than 0. The calculator will provide the theoretical hull speed in knots.

5. Frequently Asked Questions (FAQ)

Q1: Can boats exceed hull speed?
A: Yes, with sufficient power, planing hulls can exceed hull speed by rising up and planing on the water's surface.

Q2: Does hull speed apply to all boats?
A: No, it primarily applies to displacement hulls. Planing hulls can exceed this speed when enough power is applied.

Q3: How accurate is the 1.34 coefficient?
A: It's an average value. Some boats might have coefficients between 1.1 to 1.5 depending on hull design.

Q4: Why is waterline length important?
A: Longer waterline lengths create longer wave systems, allowing higher speeds before wave drag becomes prohibitive.

Q5: How does hull shape affect hull speed?
A: While the basic formula uses length, hull shape affects the actual speed achievable. Finer, narrower hulls often perform better near hull speed.