River Hull Length And Speed Calculator

Waterline Length Formula:

\[ LWL = \left(\frac{HS}{1.34}\right)^2 \]

Waterline Length (LWL):

feet

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1. What is the River Hull Length and Speed Calculator?

Definition: This calculator estimates the waterline length (LWL) of a river boat based on its hull speed using the naval architecture formula.

Purpose: It helps boat designers, builders, and enthusiasts understand the relationship between a boat's length and its theoretical maximum speed.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ LWL = \left(\frac{HS}{1.34}\right)^2 \]

Where:

\( LWL \) — Waterline length (feet)
\( HS \) — Hull speed (knots)
1.34 — Constant for displacement hulls

Explanation: The formula calculates the theoretical maximum speed (hull speed) of a displacement boat based on its waterline length.

3. Importance of Hull Speed Calculation

Details: Understanding this relationship helps in designing efficient hulls, estimating fuel consumption, and determining realistic performance expectations.

4. Using the Calculator

Tips: Enter the desired or known hull speed in knots. The calculator will determine the necessary waterline length for that speed.

5. Frequently Asked Questions (FAQ)

Q1: What is hull speed?
A: The maximum efficient speed of a displacement hull boat, beyond which it requires exponentially more power.

Q2: Why 1.34 in the formula?
A: This empirical constant represents the wave-making characteristics of displacement hulls in salt water.

Q3: Does this apply to all boat types?
A: No, this is specifically for displacement hulls. Planing hulls can exceed this speed.

Q4: How accurate is this calculation?
A: It provides a theoretical maximum. Actual performance depends on hull shape, weight, and power.

Q5: Can I calculate hull speed from length?
A: Yes, by rearranging the formula: \( HS = 1.34 \times \sqrt{LWL} \)