No one suspected that navigation on the Seine was a particularly difficult science. This is however the case and it is very difficult to recruit pilots for the Parisian boats. It is for lack of pilots that there are not more boats in circulation on Sunday!

In truth, fifteen days of learning were enough for a former sailor to fly a "fly", just enough time to learn his way; but the Navigation Service is strict: it considers that sailing in fresh water and in salt water are very different things and it imposes six months of apprenticeship, even on former sailors, even if they had done the world Tour !