At Samizdata, Brian Micklethwait has an interesting essay, including this discussion of the historical differences between naval and land powers (Athens and Sparta, Greece and Persia, Britain and France, etc.) and an insight into the odd growth pattern of the British empire after the introduction of steam power:
This contrast, between seafaring and land-based powers, has dominated political and military history, both ancient and modern. Conflicts like that between Athens and Sparta, and then between all of Greece and Persia, and the later conflicts between the British – before, during and since the time of the British Empire – and the succession of land-based continental powers whom we British have quarrelled with over the centuries, have shaped the entire world. Such differences in political mentality continue to matter a lot.
Throughout most of modern human history, despots could completely command the land, including all inland waterways. but they could not command the oceans nearly so completely. Wherever the resources found in the oceans or out there beyond them loomed large in the life and the economy of a country or empire, there was likely to be a certain sort of political atmosphere. In places where the land and its productivity counted for pretty much everything, and where all communications were land-based, a very different political atmosphere prevailed.
You see this contrast in the difficulties that Napoleon had when squaring up to the British, and to the British Royal Navy. Napoleon planned his land campaigns in minute detail, like a chess grandmaster, and he played most of his military chess games on a board that could be depended on to behave itself. But you couldn’t plan a sea-based campaign in this way, because the sea had a mind of its own. You couldn’t march ships across the sea the way you can march men across a parade ground, or a continent. At sea, the man on the spot had to be allowed to improvise, to have a mind of his own. He had to be able to exercise initiative, in accordance with overall strategic guidance, yes, but based on his own understanding of the particular circumstances he faced. There was no tyranny like that of the captain of a ship, when it was at sea. But sea-based powers had many ships, so navies (particularly merchant navies), by their nature dispersed power. In a true political tyranny, there can be only one tyrant.
More fundamentally, the sea provided freedom, because it provided an abundance of places to escape to, should the tyranny of a would-be tyrant become too irksome and life-threatening. Coastal communities had other sources of wealth and power besides those derived from inland, and could hide in their boats from tyrants. Drive a sea captain and his crew mad with hatred for you and for your tyrannical commands and demands, and he and his ship might just disappear over the horizon and never be seen again. Good luck trying to capture him. If you did seriously attempt this, you would need other equally strong-minded and improvisationally adept sea captains whom you had managed to keep on your side, willing to do your bidding even when they were far beyond the reach of your direct power. One way or another, your tyranny ebbed away.
Other kinds of tyranny, or the more puritanical sort, were also typically made a nonsense of by seagoing folk, whenever they enjoyed a spot of shore leave.
[…]
The development of mechanically powered ships, since Napoleon’s time, served to make the deployment of ships at sea a lot more like marching them about on a parade ground. First, the significance of the wind and its often unpredictable direction is pretty much negated. And mechanically powered ships are also, especially in the days of coal power, much more dependent upon land-based installations, the arrangement of which demanded Napoleonic logistical virtuosity. Much of late British imperial politics only makes sense if you factor in the compelling need for coaling stations to feed ships. Sailing ships don’t run out of fuel. Modern ships do.
Private William Penman, Scots Guards, died 1915 at 
