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. It represents the theoretical maximum efficient speed for a displacement hull.

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 boat's bow wave length equals its waterline length, creating maximum wave-making resistance.

3. Importance of Hull Speed Calculation

Details: Knowing a vessel's hull speed helps in voyage planning, fuel efficiency optimization, and understanding performance limitations of displacement hulls.

4. Using the Calculator

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

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 the 1.34 coefficient?
A: It's an average value. Actual values range from 1.1 to 1.5 depending on hull shape and other factors.

Q4: Why does waterline length affect speed?
A: Longer waterline creates longer waves, allowing higher speeds before wave resistance becomes prohibitive.

Q5: What about metric units?
A: For meters, use coefficient 2.43 instead of 1.34 (or convert feet to meters first).