How to Defend ZOMG Rushes with Monkey Subs in Bloons TD Battles

To defend heavy or continuous ZOMG rushes using Monkey Subs in Bloons TD Battles, rely on the First Strike Capability (x-4) ability combined with sell-and-rebuy micro. Standard missile spam chips away at incoming blimps, but only cycling freshly purchased First Strike abilities allows you to bypass normal cooldown timers and destroy stacked ZOMG shells before they overwhelm your track.

Submarine Upgrade Roles

Each stage of the Monkey Submarine handles a specific threat layer during late-game defense. Setting up a balanced water footprint requires assigning subs to clear camouflage, weaken blimp hulls, and deliver targeted burst damage.

First Strike Targeting and Timing

The First Strike Capability fires a missile that targets the strongest bloon on the screen. Against an undamaged ZOMG, an impact destroys the outer layer and damages the inner BFB layers based on remaining health.

To maximize ability value during a push:

• Wait for the front third: Trigger your first strike when the lead ZOMG enters the first third of the track. This prevents early ceramic spawns from escaping past your defense.
• Stagger ability activations: Avoid triggering multiple First Strikes at the exact same moment. Because the missile targets the strongest bloon currently alive, simultaneous launches can target the same ZOMG and waste an ability.
• Leverage chip damage: Allow your massed 0-3 Ballistic Missiles to damage incoming blimps before activating First Strike, ensuring the missile shatters both the ZOMG layer and the child BFBs beneath it.
• Keep an emergency strike ready: Reserve at least one active ability Submarine to catch interior blimps that slip past your primary choke point.

Sell-and-Rebuy Micro Sequence

When facing multiple stacked ZOMGs, passive cooldowns cannot recharge fast enough to protect your exit. Because a newly purchased x-4 Monkey Sub spawns with its activated ability ready to fire immediately, you must cycle purchases dynamically.

1. Fire the missile: Activate the First Strike ability from an available 0-4 Submarine to break the priority ZOMG.
2. Sell the spent tower: Immediately tap the Submarine whose ability is on cooldown and select Sell.
3. Rebuild the base tower: Place a new Monkey Sub on the cleared water footprint.
4. Upgrade to Tier 4: Rapidly purchase the middle path upgrades (0-1, 0-2, 0-3, and 0-4).
5. Launch immediately: Fire the fresh First Strike ability at the next incoming ZOMG.
6. Repeat the cycle: Continue selling and repurchasing across designated water slots as long as your cash flow holds.

This micro loop consumes substantial cash. Maintain high passive eco or strong Banana Farm income through the middle rounds so your bankroll can sustain repeated tier-4 rebuys past round 30.

Containing Child Super-Ceramics

When a ZOMG shell is destroyed, it releases fast-moving ceramics. Pure missile spam targets outer shells and can allow high-speed ceramic clusters to leak.

To secure your track exit against these leaks:

• Place Bloontonium Reactors at bends: Position at least two 4-2 Bloontonium Reactors set to "Submerged" mode directly at track choke points. Their radiation aura continuously melts ceramic rushes while buffing ability cooldowns of adjacent subs.
• Add Airburst Darts: Support your choke points with 0-2 Airburst Dart subs to clean up stray bloons that make it past the reactor pulse.
• Reserve deep water for micro: Keep central, open water areas clear for Ballistic Missile density and your designated sell-and-rebuy First Strike slots.