Depth Charge

Depth Charge is not your standard naval map...kinda like Urban Rush, but on this map you have to get the center (or not, but it helps).

Resources
High. Gems and ore on each starting island, as well as 6 derricks in the center. Also 2 derelict derricks on either left and right.

Early
The key on this map is the central island. There are 6 derricks, and often, if you can capture 1, you've captured them at least 3. But here's the rub. Soviets have weaker naval, but build faster. Allies require some time before getting dolphins.

From Oldbold

Soviet vs Allies
Power
Refinery (Infantry will only sit around in beginning)
Barracks (3 dogs, 3 engis)
Naval Shipyard (Amphibious Transport)
Radar. Build 4 scorpions and then non-stop subs (send 1 scorpion to the far-center derrick, one to your closest center-derrick. 1 to the north of the center isle and one to the south).
Refinery (sell)
War Factory (off derrick). Get as many derricks as you can obviously.
Barracks (off derrick). Get more derricks or use to defend/attack opponent on center island.
    If you get only 3 derricks, build a 3rd miner at home via an ore refinery. 
Build desolators at home for defense as well as one flak cannon to protect them. Irradiate man Irradiate! Your base should be greener than Bill Gates' wallet. Desolators defend you against sneak attacks by grizzlies/mirages, engis, tanyas, spies and can hurt passing dolphins. Desolators are amazing for naval.
Tech up, if you couldn't get all 6 derricks then race to build a kirov. Your primary goal is always the isle, capture or destroy the derricks there. This limits the amount of room the allies have to build a new naval yard and mass dolphins.
Build dreadnoughts, make sure they are always guarded by scorpions and subs in case of rocky and tanya attacks.

Alllies vs Allies

Ok. allies vs allies is prety simple. Load up on rockies. The enemy is simply forced to build rockies or get killed very fast trying to take the center. Rockies will hold off rockies. 2 black eagles or harriers will take out any transports (for sneak attacks, remember to scout). Build a transport only when you have worn down the enemy and your economy is stronger. Then get the center.
Build your 3rd black eagle or 4th harrier and use them to take out your enemy's tech center. This is critical. If you lose all 3 planes it still pays off. Try to take an indirect route and you should still keep 1 or 2 planes alive.
Note for black eagle fans, if they don't build an aegis cruiser or backup power and multiple patriots u can use a standard black eagle/rockie rush.
The reason why it's worth it to nail the tech center is that you will have dolphins first in the water. Build mass dolphins and attack. Remember to use force firing to attack with dolphins efficiently.

BO
Power
Ore
Barracks
AFC (rockies!..scout the enemy base, 3 black eagles -- 4 harriers if USA)
    If they have rockies of their own (they will) build a patriot at home.
Ore (sell)
War Factory
Battle Lab
Naval - destroyers