Navies are expensive to build and maintain not just because of the ships but also the trained crews which need paying.
If you look at the Napoleonic Wars, then in 1810 a small British army cost 2/3 of what the world's largest fleet cost. In general, you describe a situation where there are already mountains of iron on the sea, but not on land.
Thus only very rich nations maintained large standing fleets in times of peace.
Hmm. In fact, for most of history, the great maritime powers west of the Indus are city–states. Large only by the standards of city states. The middle ones are some kind of Samos. Then a break for the Hellenists and Rome, and again the Italian "polis" in the south and the Hansa in the north.
At the same time, if we take the X-XI century, then the Mediterranean Catholic hegemon is Amalfi, 50 thousand.
Portugal, which began to engage in the navy in the 15th century, was in fact a power of about the same order as Venice, while quite poor.
The real superpower of the West (France) was engaged in the fleet from time to time until the 1660s.
That is, there were two real reasons to take up the fleet. 1. The presence of not so much money and opportunities 2. HOPELESSNESS. In different forms – Lydians, Spartans, Spaniards, etc. In general, an invincible opponent on land.
So war fleets were mostly composed of ships and crews "borrowed" from merchants.
In reality, this is a rather specific situation: "we forgot how to use a battering ram, but we don't have powerful guns yet and we are not Byzantium/Arabs."
At the same time, the high possibilities of mobilization were largely explained by the extremely militarized style of merchant shipbuilding.
A normal merchant ship before the Renaissance is something like a Greek "round" ship (a smooth-decked sailboat).
The whole horde of ships with massive bow and stern superstructures are, in essence, military "projects" adapted for commercial needs, and not vice versa. The merchant galleys of the Mediterranean are exactly from the same series.
As for the crews, the possibilities are not as great as they seem. The crew of merchants is minimal for financial reasons. At the same time, the movement of sailboats from point A to point B does not require large crews, even a fairly large ship can manage a couple of dozen sailors. Meanwhile, even a small frigate needs six times more.
With the dominance of the rowing fleet, the situation is almost the same.
That is, in order to recruit the military fleet mobilized, the merchant fleet must be orders of magnitude larger than the military. Meanwhile, for the maritime powers, the situation often resembled a "Dune". The Dutch played the role of the guild, then the British, and no one canceled the need to keep the fleet inside the system.
Let's move on to the material part
There are three problems with the use of mobilized merchant ships
1) first you need to have them. At the same time, if we take the top 10 European maritime powers of the 18th century, we will find that half of the merchant fleet either has practically no, or it is small, especially relative to the size of the military.
2. they should be suitable for military functions. Meanwhile, a) the vast majority of "merchants" until the very end of the era of the sail is a small, while warships grew at a faster pace. b) a very slow and clumsy.
At the same time, the rowing fleet is either a ram or artillery in the nose, and the sailing fleet is a broadside. A little earlier – a specific "boarding" design with "locks" on the bow and stern, etc.
3. Mobilized merchants are determined... and resolutely avoid combat. If De Ruyter has surrounded the British, the Dutch traders simply won't do anything. If there is no De Ruyter, and there are no Englishmen in the environment… In general, you understand.
As a result, a clear specialization raged in the rowing fleet throughout antiquity and since the 16th century. There were exceptions, but it was force majeure (the guns are too big to put them on a war galley, so we will improvise – but at the first opportunity we will write off the "mutants").
In the sailing fleet, the situation looks like this. Already at the Battle of Lawforth (1665), the mobilized "merchants" make up less than a quarter of the fleet of England and about 1/9 of the fleet of Holland. At the same time, we are talking about the East Indians and Co. That is, these are initially hybrid military-merchant ships with teams whose problem is only in discipline and lack of experience in squadron battles. Moreover, the ships are atypically large, there are fractions of a percent in the merchant fleet.
In general, the situation very quickly begins to resemble the Second World War. Mobilized and converted ships can be used for escort and limited for privateering functions, but no one uses them in regular battles.
This is most extreme during the classical period where oar powered galleys and triremes literally required crews on par in skill to modern competition rowers.
In reality, the rowers were recruited at best from poor backgrounds or soldiers. At the same time, they often made up a significant part of the adult male population.
In general, the secret is simple. We take people who are used to physical labor and start feeding them with superhuman strength. If you still pay a lot or flog a lot...
Naval combat was mostly about boarding and capturing enemy ships.
Yes, and even more than you think.
This had its heyday during the classical period but was newer too popular because ramming an enemy ship in such a way to destroy them but NOT cripple your self in the process and doing so during a pitched naval battle was a difficult task that required a skilled crew and well coordinated fleet.
You are exaggerating the scale of the problem. With the classic galley tactics head-on, the enemy at first remained without oars. And it is quite difficult to miss a slowly crawling hull with a length of at least 30 m.
The fact that the ramming tactics did not revive quite quickly has one explanation. The owners of the sturdy galleys in the east relied on Greek fire. In the west, such ships appeared not much earlier than artillery. In later European galleys, the ram was simply replaced with a large-caliber bombard.
