I’m sure many, if not all, have had the experience of a guest getting a little nervous when the yacht heels. Our normal response is “she can’t capsize as she has a heavy keel”. Well how sure are you of that and how do different yachts shape up as far as stability and comfort is concerned.
Some of the formulas such as STIX are extremely complicated which, quite honestly, you need to be a rocket scientist to understand.
Capsize Screening is however a simple formula and certainly provides a yardstick of stability and stiffness. The ideal capsize screening ratio is less than 2.
The ideal Comfort Ratio figure is over 20. Essentially this means that you can enjoy your Gin and Tonic in relative comfort while sailing when those less than 20 might be spilling more than they consume.
Ted Brewer is the brains behind these ratios and I take no responsibility for their accuracy or my calculations. Please therefore treat them with “a pinch of salt”. However going through the list it does, in most cases, make sense.
The table below sets out the capsize screening and comfort ratio of a number of yachts which should be familiar to most.