I'm sorry, Mrrzy, but it is indeed wrong to apply the word "soldier" to any member of the armed forces without distinction.

Every European language, without exception, has specific words to distinguish soldiers from sailors, even those serving in warships, and I'll bet money that Asian and Semitic languages do, too. The line between soldiers and airmen is a bit fuzzy, but only a bit; it is, after all, only a century since the first air forces were split off from their parent ground forces. But seamen have never been soldiers, even in antiquity.

We Canadians are rather more aware of the nomenclature issue that most people. Between 1964 and 1968, our armed services were first integrated and then unified to form the Canadian Armed Forces as they exist today, and the old rank and trade structure and terminology were swept away with the stroke of Parliament's pen. The Royal Canadian Navy was severely discombobulated; suddenly, no one knew what to call the person in command of the ship because, suddenly, a captain was a junior officer. I have a lovely photograph from 1965, showing a bearded man in a sailor suit with the crossed anchors of a Petty Officer 2nd Class on the sleeve as he hoists the new flag (the Maple Jack, as my Dad always called it) at HMCS Gloucester, a shore station. The caption, written in the politically correct form of the time, identifies the bunting tosser as Sgt(S) -- that is, Sergeant (Sea) -- John Doe.

Of course, it did not last. Most of the naval ranks never went away in real life -- by 1972, when I joined up, Petty Officers were Petty Officers again -- but ships never got their captains back; they had morphed into Commanding Officers, and their First Lieutenants had become Executive Officers, as in the U.S. Navy.

By the way, the fact that matelots of the Royal Navy (British, that is) were occasionally organized to fight more or less as infantry or artillery only proves the rule. There's a famous print from the Illustrated London News (I think) showing sailors in square rig attacking the walls of Lucknow ... with naval guns that they had hauled all the way from Calcutta.