You said: "... it took (and takes) a lot longer to train a sailor than a soldier since, as I mentioned before, the essential part of a naval officer (sic) or seaman's training is shiphandling in all weathers. Therefore, if you do not go to sea in all weathers, you don't get the essential training.
In itself, that is an unexceptional statement -- well, except for some who actually train soldiers. (The ~ 16 weeks training for conscripts in a general mobilization produces alert cannon fodder without their being mixed with veterans.) However, you leave out too much.
The sailing navy which recruited only landsmen had great problems. Most navies relied on recruitment from merchant and fishing fleets. A serious consideration in government control of colonies was not only commerce for home-land ports, but also the merchant fleet to carry the goods and provide basic training to sailors. The use of the Grand Banks by the French fishing fleet was such an important element of the maintenance of the navy that it influenced the settlement of the 7-Years War.
Just as a sailing navy could not spring to life or double or triple itself in a year without a shipbuilding industry that relied on a very long pipe-line of wood specially selected in the forest and aged under supervision in the dock-yards, it had to have all that to maintain itself. Meanwhile, it also had to have a manpower pipe-line which allowed youths to gain basic experience at sea, or perhaps more importantly - weed-out those who could not adjust to the rough physical and unique mental life at sea. The national leaders of France understood that. The Revolution was a speed-bump that Britain didn't suffer.
Whilst trying to convict Napoleon of stupidity, it seems too often that how the cards that fate dealt France were played is not a consideration. It seems only a matter of castigating the holder of the cards -- particularly for being in or staying in the game.
No one seems to dwell on how Spain had historical advantages similar to Britain's for building a great navy. Somehow the player of Spain's naval cards seems to have squandered them.
Back to the point -- it was not just putting the navy ships out to sea in all weathers. It was a matter of military manpower overall.