1. What is the Boat Speed Formula?

The boat speed formula estimates a vessel's maximum speed based on engine power, boat displacement, and hull type factor. It's particularly useful for displacement hulls where speed is limited by hull wave-making characteristics.

2. How Does the Calculator Work?

The calculator uses the boat speed formula:

Where:

• \( Power \) — Engine power in horsepower (hp)
• \( Displacement \) — Boat weight in pounds (lbs)
• \( Factor \) — Hull type factor (typically 1.34 for displacement hulls)

Explanation: The formula shows that speed increases with power but decreases with the square root of displacement. The hull factor accounts for different hull efficiencies.

3. Importance of Speed Calculation

Details: Understanding potential boat speed helps in selecting appropriate engines, estimating fuel consumption, and planning voyages with realistic speed expectations.

4. Using the Calculator

Tips: Enter engine power in hp, displacement in lbs, and hull factor (default is 1.34 for displacement hulls). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical hull factor value?
A: Displacement hulls: ~1.34, Semi-displacement: 1.5-2.0, Planing hulls: higher values (but formula less accurate).

Q2: Why does speed increase with the square root of power?
A: Because wave-making resistance increases exponentially with speed, requiring disproportionately more power for small speed increases.

Q3: Does this work for all boat types?
A: Best for displacement hulls. Planing hulls exceed this theoretical "hull speed" by rising over their bow wave.

Q4: How accurate is this calculation?
A: It provides theoretical maximum speed. Actual speed depends on hull cleanliness, sea conditions, and loading.

Q5: What's "hull speed"?
A: The speed at which a displacement hull's bow wave equals hull length - beyond this, speed increases require enormous power.