1. What is Hull Speed?

Hull speed is the speed at which the wavelength of a boat's bow wave equals the boat's waterline length. Beyond this speed, resistance increases dramatically as the boat begins to climb its own bow wave.

2. How Does the Calculator Work?

The calculator uses the hull speed formula:

Where:

• 1.34 — Empirical constant for displacement hulls
• LWL — Load waterline length in feet

Explanation: The formula calculates the theoretical maximum speed of a displacement hull boat before wave-making resistance becomes dominant.

3. Importance of Hull Speed Calculation

Details: Knowing a boat's hull speed helps in understanding its performance limitations and fuel efficiency. Exceeding hull speed requires exponentially more power.

4. Using the Calculator

Tips: Enter the boat's waterline length in feet. The value must be greater than zero. The result shows the theoretical hull speed in knots.

5. Frequently Asked Questions (FAQ)

Q1: Does this apply to all boats?
A: No, this applies primarily to displacement hulls. Planing hulls can exceed this speed with sufficient power.

Q2: Can a boat exceed its hull speed?
A: Yes, but it requires significantly more power and typically involves transitioning to semi-planing or planing modes.

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

Q4: Does hull speed change with load?
A: Yes, as loading affects the waterline length. More load typically increases LWL and thus hull speed.

Q5: What's the constant 1.34 based on?
A: It's derived from the relationship between wave-making resistance and waterline length in displacement hulls.