Chapter
Displacement, ballast, stability and technical ratios
Ballast percentage is a starting point, not a safety conclusion.
Start this chapter ↗Ballast percentage is a starting point, not a safety conclusion.
A simple screening formula does not describe a complete boat’s stability.
Ted Brewer’s index is an empirical comparison, not a comfort measurement.
Total weight and weight intended for stability are different concepts.
In this chapter
Lesson · 3 min
Displacement and ballast
Total weight and weight intended for stability are different concepts.
Lesson · 3 min
Ballast/displacement ratio
The percentage of displacement accounted for by ballast.
Lesson · 3 min
Displacement/Length Ratio: weight for length
D/L relates displacement to waterline length.
Lesson · 3 min
Sail Area/Displacement: sail for weight
SA/D compares sail area with a displacement-related scale.
Lesson · 3 min
Comfort Ratio
Ted Brewer’s index relates displacement, length and beam.
Lesson · 3 min
Capsize Screening Formula
A formula comparing the boat’s beam with its displacement.
Lesson · 3 min
STIX, AVS and stability
What STIX and AVS indicate about stability and recovery after heeling.