: The beauty of the metric relationship is that one litre of
: displacement basically equates to 1 kilogram of flotation. So
: you can quite easily calculate displacement when planning
: adjustments to designs.

The imperial system was centuries ahead of the metric system; everything is decimal in metric based on the arbitrary happenstance that humans have 10 fingers - provided they don't get too cosy with their table saw. Imperial inches are available in a complete set of binary fractions, the way computers work. Any mathematician will tell you that is fundamentally better . . . so will most boat builders. Hexadecimally speaking 1/16th is close enough for me!

Personally I work in whichever system suits the job; metric is fine for small stuff, but if I am building a metric design I convert it to imperial first because it is easier to make a mistake measuring with a metric rule than an imperial one. The simpler calculations of the metric system really don't mean a thing when you are building. Metric was created by scientists not builders.