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Freeboard Calculator

Estimate the safe freeboard for your boat based on its dimensions.

Quick Samples
Try these common configurations to get started

30ft Cruiser

Coastal cruising sailboat

25ft Sport Fisher

Offshore fishing boat

18ft Skiff

Inshore flat-water skiff

Hull Dimensions
Enter your boat's principal dimensions

feet

feet

feet

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About This Tool
The Freeboard Calculator helps you determine one of the most critical safety aspects of your boat's design. Freeboard is the distance from the waterline to the deck, and having enough of it is essential for preventing waves from swamping the vessel. This tool provides an estimate of the minimum safe freeboard based on common naval architecture principles, helping you assess if your boat is safely loaded and designed for its intended waters.

Key Concepts:

Freeboard: Height of the hull above the waterline.
Reserve Buoyancy: The volume of the hull above the waterline that provides lift as the boat heels or encounters waves.
Seaworthiness: A boat's fitness to handle the conditions it may encounter.
Downflooding: The point at which water can enter the hull through openings. Freeboard is the primary defense.
Frequently Asked Questions

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