1. What is Max Boat Speed?

The maximum speed of a displacement hull boat is theoretically limited by its waterline length (LWL). This is known as hull speed, beyond which the boat starts to climb its own bow wave.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( LWL \) — Waterline length in feet
• 2.5 — Empirical coefficient

Explanation: The square root of the waterline length determines the wave-making resistance, which is the primary speed limiter for displacement hulls.

3. Importance of Waterline Length

Details: Waterline length is a crucial measurement in boat design as it directly affects the boat's speed potential, stability, and wave-making characteristics.

4. Using the Calculator

Tips: Enter the boat's waterline length in feet. The value must be greater than 0. The result will be in knots (nautical miles per hour).

5. Frequently Asked Questions (FAQ)

Q1: Does this apply to all boat types?
A: This formula applies primarily to displacement hulls. Planing hulls can exceed this speed with sufficient power.

Q2: What is a typical waterline length?
A: For a 30-foot sailboat, LWL might be 25-28 feet. The LWL is usually slightly less than the boat's overall length.

Q3: Can boats exceed this speed?
A: Yes, with enough power some boats can exceed hull speed, but it requires exponentially more energy.

Q4: What affects actual boat speed?
A: Besides LWL, factors include hull shape, displacement, sail area or engine power, and sea conditions.

Q5: Why is the coefficient 2.5?
A: This empirical value accounts for the relationship between wave length and boat speed in knots.