- Sink the USS Hornet and the USS Enterprise before they escape across the northern border
- The Yamato must survive
Arguably the easiest ship challenge mission out there, the Yamato is a behemoth of a ship and, for the duration of this mission, is under your command.
The first thing you're going to notice though is that the Yamato has far fewer guns than, say, the Fusō class. All its guns are concentrated in its turrets and, while its turrets have tremendous firepower and range, chances are they'll be disabled by either enemy warships or dive bombers. This gives the enemy carriers a chance to make a run for it. You're still faster than they are, though.
Breaking the Screen
The Yamato is escorted by a Kuma class and two Fubuki classes. Out of the two, the Fubukis are the most essential. They are extremely good in the anti-aircraft and anti-submarine role, and you're going to need both if you are to ensure the survival of the Yamato.
For now, though, let the Yamato lead and have all personnel set to water repair duty. The enemy screen consists of a lot of destroyers and a few cruisers, including the USS Houston. None of them are a match for you at all, and their major damage is done by torpedoes, which are relatively easy to avoid. Simply have your ships duke it out against the screen and you should penetrate it with few or no problems.
The destroyer's cannon shells will merely bounce off your hull and do little to no damage, so focus instead on the cruisers. That said, attack any ship trying to sink your destroyers. The mission becomes quite difficult if they are sunk. Conversely, you can use your Kuma class as bait. It doesn't matter if they sink the Kuma.
Now is when you encounter the unexpected - enemy submarines. This is why you have to keep your destroyers up and running at all times.
There are two enemy subs - the Nautilus and the Narwhal, so have your destroyers immediately go for them. The AI is quite smart in using its torpedoes, so if it launches, chances are you won't be avoiding them. The quicker your destroyers sink the enemy subs, the better.
There is no real tactic in sinking the enemy subs, but have them rejoin with the Yamato once both subs are down.
Also be on the lookout for air-dropped torpedoes. SBD bombs cause little to no damage, so don't worry too much about them. Your deck armour is next to impervious. Just worry about torpedoes, torpedoes, and nothing but torpedoes.
Skies Against You
Now is when the Hornet and Enterprise start launching planes at you. They are backed up by a LOT of planes - SBDs and Devastators. Fortunately they'll all come from the front, so arrange your destroyers in front and have them screen against the waves of land and sea-based bombers. Fortunately there's only one wave of land-based bombers, so once they're down, you'll have only to deal with intermittent bomber wings from the Hornet and the Enterprise. Both may have an infinite number of planes, but it can still only send up three squadrons at a time. Your destroyers can handle these easily. Use the formation screen to set up your screen.
As soon as you're in range, merely shell the living daylights out of the two enemy carriers. Don't bother turning to broadside, but do bother fixing your turrets. Dive bombers may disable them, so you'll want to lay down as much feather as you can on the enemy carriers to send them to the bottom.