Why a Ship's Speed Is Measured in Knots: Actual Knots, in a Rope
Sailors threw a piece of wood into the sea, counted the knots in the rope behind it, and timed it with an hourglass. That is why speed is in knots.
Making Sense of Vessel Data
Hull performance, emissions rules and charter party claims all come down to numbers. Here is how to work them out and defend them: fifteen years of daily practice by Christos Papandreou, written down and taught.
The Academy, counted
Read from the courses themselves each time this page is built.
- courses
- 39
- lessons
- 300
- quiz questions
- 2,567
- hours of lessons
- 48
- specialisations
- 9
See every course →7 courses are free in full, and the first lesson of every paid course is free.
Latest Insights
Papers, articles, and talks on vessel data.
The Circle Painted on Every Ship Because One Man Lost His Temper
The circle on a ship's hull is there because one angry member of Parliament fought owners who overloaded ships for the insurance money. It still sets how deep a ship may load.
Energy-Saving Devices: Collecting the Propeller's Leftovers
A propeller leaves a third of its power behind in the water: spin in the slipstream, a vortex off the hub, and an uneven wake. ESDs are fixed steel aimed at those named losses: 1–5% each, forever, if the device matches the hull.
Who We Are
Blue Autonomy is a maritime research, publication and academy project by Christos Papandreou. We publish our methods, findings, and mistakes openly rather than treating them as trade secrets.
How we work
Checked before it goes out
Every figure is worked from a source you can open, recomputed before publication, and corrected in the open when we get one wrong.
Plain language, real physics
Behind every result sits real physics and statistics, and we explain both in plain language. A result you cannot understand is a result you cannot trust, on the bridge or in the boardroom.
Published, not guarded
Methods, findings and mistakes are shared openly in papers, articles and talks, instead of being treated as trade secrets.
Contact Us
If something you read here raises a question, or there is a subject you want covered, write to us. We answer ourselves. Email info@blueautonomy.gr or call +30 6984585624.