Alright, while I continue to try and pull this chapter out of my head like a tooth from a rabid dinosaur, I came up with a little bit that might help for making the setting more 'firm' for all of you readers. Enjoy!
A Brief Look at the War of the Waves: Part One
Black Day was the day that the Abyssals made themselves known to the world, attacking various ports and ships across the globe. This was also the time that brought forth the first ship-girls, such as Akagi, Iowa, Warspite and Tirpitz, who aided in humanity's defence when they least expected it yet most needed it. The mad dash to mobilize everything while simultaneously fighting off the Abyssals' seemingly random attacks was referred to by humans as Blood Week, with the world reeling in response.
The Abyssals however, do not see it as simply Blood Week, but rather the Year of Blooding. This is because on their side of the waves, they were uncoordinated, spread out, and had no functional leadership. As more and more Abyssals came back, attacking and prowling about as they will, the first batches of Abyssals started vying with each other for leadership and territory. Thus, it was as vicious below the waves as it was above on the surface, with Abyssal killing Abyssal as they fought for dominance. As weeks went by however, it became obvious that simply sinking their fellow Abyssals was only a temporary means to try and force their wills on each other, as they could force themselves to resurrect after a while to fight and kill again. This meant that the Abyssals themselves needed to form some sort of structure or they risked being bogged down with each other more than humanity, who they knew would not be paralyzed with fear and confusion for too long.
Thus, several of the oldest and most powerful of the Abyssals argued and debated with one another as to how to solve this, eventually coming up with the system of hierarchy that they use now. Basing themselves first on a sort of 'cult of personality' to establish groupings of Abyssals, those that others deferred to would be known as Princesses, while others would have various ranks if given their own command structure beneath them. Many wondered if this meant that one of them would claim to be an 'Empress' of sorts, but between the threat of this fragile society falling apart in infighting, the question of a need for such a rank, and the silence of the Abyss itself when asked if it would nominate someone on its own, none have really pushed to take the Throne of the Seas. Many Abyssals therefore believe that until the matter with humanity is settled, it will remain empty, and that the one who will fill it will be the Princess that proves to be most successful in the war. Not every Abyssal follows a Princess though. There are quite a few small fleets or flotillas that go their own way, though these tends to be more nuisances to humanity than their more organized and established sisters.
During the second year or the war, the Princesses succeeded in finding ways to organize and sustain their own hidden ports and shipyards, as well as the first 'True' Abyssals, so-called because their bodies were forged by the hands of their sisters, rather than simply echoing their old human-made shapes as they did when they first awoke from the deep. This further set a divide between the Royalty and those not willing to follow, as it meant that True Abyssals could modernize themselves and tailor their forms and weapons to better fight humanity, while those without were pushed back further due to their more obsolete equipment. Some of these 'Pirate' Abyssals make up for this by trading supplies, resources, or other things to various Princesses for more modern equipment, but ultimately it meant that for most it was either join with the Royalty, or be crushed between them.
However, humanity had not been idle either. Learning from several examples during Blood Week and other battles, new strategies were developed to combat the growing threat from beneath the waves, along with equipment tailored now to fight back on more equal terms. Several of humanity's weapons were still head and shoulders above the Abyssals' in terms of effectiveness, but being able to deploy them against those in the deep were another matter. Sonar nets and buoy networks worked intermittently, and radar as well had diminished use against their enemies' more supernatural forms and powers. However, by working alongside the ship-girls that had joined humanity, integrating them alongside more conventional assets, it allowed for an ad-hoc means of creating a sensor network. The Anansi Network was created that allowed a ship-girl's own radar and sonar to be broadcast to conventional ships meant that fleets could more accurately target the enemy, while a ship-girl could fight in ways and areas that a normal ship could not. It was also during this period that the first true Summoning Chambers were designed and made to a set standard, as while the majority of the world was still questionable about magic and its workings, it had finally been acknowledged as a world fact and dedicated research was put into place.
The third year saw the resurgence of the Abyss in full, with entire fleets of True Abyssals now stalking the waves. while humanity rolled out its own fleets and weapons to counter them. This part of the campaign was just as vicious as the first year, as multiple nations threw their weight against their undersea counterparts, with multiple battles across the Atlantic, Pacific, Indian and Arctic oceans resulting in thousands of deaths and billions in damages to the world's cities...