I like this map, so here's a longpost detailing all my thoughts and first impressions.
OVERVIEW:
It's a pretty small map, with two disconnected center areas, each having a +-sign-ish thing in the middle and two ramps, and an area outside of each spawn point connected to both center parts, each giving two methods of entry to the center areas, which can both be used to access your side as well. It's feels very cramped, especially in those center parts, and it seems really easy to take over one area and sneak-attack a team not paying attention to both sides or who just loses everyone on one side.
Also, there's water around the stage, which you can fall in pretty easily (or be pushed into) if you're not careful. Which I have. Repeatedly.
Spawn Point & Pre-Center:
There are three grate paths down from the spawn to the pre-center area on each side, as well as two places you can just drop down from to reach the pre-center area, so it's probably not that easy to spawncamp unless your whole team is dedicated to it, since there are several avenues out of the spawn point. The pre-center area is a long horizontal area with a lowish ramp in the center, a tallish box on each side that can be used for cover, and a small box on each side near the ledge that can be used to shoot into the center areas. You can enter the center areas three ways from here:
1) You can jump down from the area near the center of the pre-center, which has a wall that can be inked up. A fairly obvious entry point, but the fastest one.
2) you can go the the far side of pre-center, which has a wall you can hide behind, then has a wall you can jump down, which, again, can be inked up. This is probably the best sniper point of the entryways, since you have the wall to hide behind, but it takes the longest to reach. Additionally, it's a bit tricky to get at someone who hides in here (at least in my experience), since you can only get at them from two directions.
3) you can jump from the pre-center area farther from the middle to the center area (near the little box). This one is the fastest, but you cannot retreat as easily from here as from the other two entry points, and if you misjudge the distance you can fal into the water, which dissolves you and makes you wait to respawn. I have done this.
The Centers:
Yes, centers. There are two rectangular center areas, each with a sorta-+-sign-shaped just-above-Inkling-height wall structure in the middle of each one, a pair of ramps closer to each side (not sure what these are for, honestly), a rectangular tarp thing that cannot be inked right on each side between the two entry-point walls. It's really small, which makes it feel very combat-heavy. It has the +-wall and the ramps for coverage, though all of them can be inked and traversed, so it's not completely safe, but nothing is safe in the center. The centers are unconnected, with no way across, but you can shoot across.
Additionally, you can ink up the walls in the center to reach each side's pre-center area.
Turf War Thoughts:
I think the most balanced way to attack this stage is to send one person into each center area, with a Charger/Squelcher/ or maybe .96 Gal and Dynamo Roller (normal or Gold) on each side's pre-center to act as a sniper or just provide supporting fire. Once you hold a center area, you can have that side's duo move up into the enemy's pre-center, harassing enemies on their side and covering their side in ink. I wouldn't recommend moving Chargers up, since they should do best from an elevated position to shoot down into the center, but definitely move Squelchers, .96 Gals and Dynamos into the center.
For the Inkling fighting in the center, you can choose between a fast-firing shooter (superior fire rate, but generally crap for combat; either hide in ink to score surprise splats or hope your sniper is good), stronger shooters (not great for turf coverage, but better for combat, so you don't need the sniper as much), rollers (great for turf coverage and good at close combat, but will need sniper support to deal with ranged foes) or Blasters (ultra-powerful, but crappy for turf coverage). Maybe you could use Inkbrush (speed is nice, and the loadout's good, but the area might be too small to take advantage of your speed and the low power and range could be problematic).
For the sniper, use a Charger (non-Squiffer, preferably, since range is needed for this, but they're the obvious choice and can 1-shot enemies; watch out for ambushes though) and Squelchers (not as good for super-long-range, but better for when you get ambushed). Maybe you could use a .96 Gal or Dynamo Roller (might not have enough range, but they're very strong and their loadouts let them cover areas quickly with Sprinklers or Inkstrikes).
Alternatively, you could replace the snipers with two teammates who go wherever they are needed. These teammates could use either a Splat Roller (not sure the Killer Wail would be good here, but Suction Bombs are nice), Krak-On Roller (Squid Beakons are great for getting teammates back into the fight quickly, though I'm not sure you'll need them on a map this smallish, but the real attraction here is the most mobile special in the game, the Kraken, which is awesometastic here like it usually is), either Dynamo Roller (not as fast, but HUGESWINGS give it range and power over the other rollers, and you can cover areas fairly quickly with Sprinklers or Inkstrike; in fact, Inkstrikes are a great support special in general since you can hit anywhere with it) or possibly an Inkbrush (very speedy, to get around quickly, and Sprinklers and Inkstrikes make it great for turf coverage and team support, but it may not have enough power and its range is awful; purely for turf coverage, only use if your teammates can handle combat without you most of the time) or Aerospray/Splattershot Jr. (really fast firing and wide spread is great, but you'll have to run away from fights sometimes; less often with Jr. because you have Bubbler, but you're not winning most firefights with these weapons, so rely on someone else for splattering people most of the time and focus on covering turf).
Splat Zones Thoughts:
The map changes a bit in Splat Zones. The Splat Zone is on one of the center parts, with the other having two ramps that you can jump off of to reach the area with the Splat Zone. This changes how you play the stage completely, as most Splat Zones levels that i like do, by making the fight about a single area. However, the center area without the Splat Zone cannot be ignored, since you can access the side with the Splat Zone through it, as well as accessing the other team's pre-center, which can lead to snipers getting wrecked from the side before their teammates in the center get sandwiched to death and control of the Splat Zone changes hands.
I think the best way to approach this map is with a setup like this:
(1) Dedicated Zone Fighter: Jumps into the Pit Of Death that is the Splat Zone and fights from there, covering the Zone when enemies aren't around.
(2) Dedicated Sniper: Stands on the edge of pre-center and snipes from there with a Charger.
(3) Harassment & Secondary Zone Fighter: Goes after the center area without the Splat Zone, either to get into the Zone via the ramps or to attack the enemy team from their pre-center.
(4) Dedicated Support: Can either go into the Splat Zone with (1), guard (2) if an attack is coming from the side, or aid (3) in going down the center area. Generally supports whoever needs supporting.
Alternately, you can get rid of the Dedicated Sniper for a second Dedicated Support.
Weapon Type Usefulness Thoughts:
Shooters: Useful as always, but you might want more powerful shooters for this stage because it's smaller, or to get Inkzooka or Bomb Rushes frequently otherwise.
Chargers: Fairly useful, mostly for scoring splats against enemies in the center areas, but watch out for ambushes.
Squiffers: Yes, I'm aware this is a Charger, but I feel it's different enough to warrant a separate analysis. The Squiffers might be able to snipe a bit, but their shorter range and lack of arcing shots can leave it less useful for fighting through the center. Still, these might be useful for spawncamping, since they charge quickly, splat in 1 shot and still outrange most weapons. Again, be wary of being flanked, but your fast charging can somewhat mitigate this.
Rollers: Not sure these will be useful. The Krak-On will be the most useful, simply for having Squid Beakons to get teammates to areas quickly and the Kraken for pretty much anything, but Dynamo Rollers could be useful as well, since they can splatter foes easily with their tidal waves of ink and can cover the center area they're not in decently by tossing over a Sprinkler. Gold Dynamo Rollers could be useful too, but more for combat than turf coverage, since they have Splat Bombs instead of Sprinklers, and can support their team from anywhere with Inkstrikes.
Blasters: Should be pretty useful in a smallish map like this. Custom is probably better here, since it has Bubbler, but all of them should be fine.
Inkbrush: A mixed bag. It's fast, and it can cover turf like no other thanks to its speed, Sprinklers and Inkstrikes, but its weak, short swings hurt its combat ability. It could work, especially in Turf War, but I dunno.
Final Thoughts:
I like this stage. Despite being a very close-combat-y stage and not having much room to manuever in those center parts, I feel like it's fun to play on. Splat Zones is kinda chaotic, but that might have been my team forgetting the other side of the map exists.
I was expecting to hate Splat Zones here for the same reason I hate Port Mackerel's Splat Zones, because spawncamping feels like a requirement for winning, but the single Zone makes spawncamping feel kinda unnecessary since you can focus your whole team on one area instead of having to spread your team thin covering both Zones. I don't like it as much in Turf War, since I can't cover the whole center by myself, but it's nice too.
So overall, yeah, this map is a nice addition. I'll probably enjoy it more after the August update, but it's fun now too.
Also I could be completely wrong about all of this. Wouldn't surprise me at all, actually.