Why attacking in columns demanded trained crews

Navies had pursued the idea of breaking an enemy line for roughly a century before Trafalgar. The attacking ships still had to close on what were effectively floating artillery forts while taking fire they could not yet return. Columns could divide the opposing line and concentrate force, but the approach was dangerous and difficult to coordinate under sail. The Franco-Spanish leading ships could not turn back into the fight quickly because every maneuver depended on the available wind. British crews therefore needed self-discipline as well as training, since casualties could remove the officers and petty officers who normally enforced order.