How Do You Beat a Calamity Tower Solo in Once Human?

Quick Answer

Follow the main quest to Sunken Oath, the first Calamity Tower, and bring a warship equipped with a working cannon and sufficient ammunition. Destroy the attacking tentacles, fire at the weak point when it becomes exposed, and follow the beam down to the tower’s base to claim your reward. The later Long Lament encounter uses the same central combat sequence but requires another round of ship preparation.

The first Calamity Tower is a major equipment checkpoint in Isles of Abyss. Your character may already be Level 50, but higher-tier gear remains unavailable until you complete the required tower challenges.

You fight these enormous sea creatures from your ship, moving around the tower while destroying its tentacles and exposed weak points. A simple warship can complete the first encounter alone. Large, elaborate ships are not necessary, and poor cannon placement can make a more expensive vessel harder to fight with.

There is also a second objective after the creature dies. The reward is not automatically finished the moment the tower stops attacking. You must reach its base, find the loot, and collect it before leaving.

Which Calamity Tower Should You Fight First?

Sunken Oath is the first Calamity Tower encountered through the main story. After completing the preceding quests and preparing your warship, follow the objective directing you to sail out and challenge it.

Your current main quest matters more than whether another player has already defeated the tower in the world. A server may have completed its first clear while your character still needs to finish the associated encounter. A previously defeated tower elsewhere in the world does not automatically satisfy your personal objective.

The first fight leads into the Reefshadow Bay portion of the story. Later, after the Voyager and Gray Rock Mine Ruins objectives, the main quest directs you toward Long Lament.

These are separate milestones. Completing Sunken Oath does not automatically unlock every subsequent equipment tier.

The current task marker identifies where you need to sail. Bring your warship into the challenge area rather than searching the surrounding islands for a conventional dungeon entrance.

How Many Cannonballs Do You Need?

The Sunken Oath preparation objective recommends 60 cannonballs, while the Long Lament preparation objective recommends at least 130. These are preparation recommendations, not the exact number of shots required to defeat either tower.

Actual ammunition consumption depends on missed shots, the damage of your installed cannon, how quickly you destroy tentacles and capitalize on exposed weak points, and whether you also deal damage with personal weapons.

Before setting sail, check three things:

• Cannon ammunition: Carry enough for multiple tentacles and the exposed weak-point stages. A few missed shots should not leave you unable to finish the encounter.
• Ship condition: Repair damage sustained during exploration or a previous naval battle.
• Weapon placement: Confirm that your cannon can actually fire toward the side of the tower you intend to attack.

That last check can matter more than carrying an additional stack of ammunition.

For an early tower, prioritize a reliable firing position and enough ammunition over an expensive redesign. A compact ship is easier to turn toward moving targets and away from incoming attacks.

If your ship struggles to move, turn, or aim its weapons, check the Ship Building guide before committing more resources to another attempt.

How to Destroy the Calamity Tower’s Tentacles

Once the battle begins, the tower attacks from the water with large moving tentacles. The first task is to destroy those exposed targets while keeping the ship moving.

The tentacles are not stationary firing targets. They rise, shift position, and force you to adjust your angle. Firing repeatedly from a poor position wastes ammunition and allows the tower’s area attacks to continue pressuring your ship.

Keep Moving While You Fire

Approach with enough space to maneuver rather than pushing the ship directly against the tower. Watch the incoming area attacks and the position of the active tentacles.

With a suitable cannon installation, you can continue steering while aiming and firing. Right-click aiming was used successfully during a Long Lament encounter, allowing the ship to reposition without stopping for every shot.

The useful pattern is to move until a tentacle is within your firing arc, attack it, and adjust your course when the target shifts or the tower begins another attack.

It is possible to lose more time turning an oversized ship toward a tentacle than actually damaging it. On a compact vessel, a short course correction is often enough to bring the target back into view.

Attack the Exposed Weak Point

Destroying a tentacle creates an opportunity to deal substantial damage to the tower itself.

Watch for the exposed weak point or vulnerable structure. The encounter indicates that destroying the exposed target deals heavy damage to the tower. Shift your aim away from the surrounding water and concentrate fire on that opening.

During Long Lament, the fight includes attacking the tentacles and identifying the exposed structure before the tower finally falls. Simply shooting whichever part is closest is less efficient than responding to the current vulnerable target.

When the opening ends, return to the remaining tentacles and reposition for the next exposed target.

The encounter is complete only when the tower is defeated and the post-battle objective appears.

Sunken Oath Solo Strategy

Sunken Oath can be cleared solo with a basic warship. One successful attempt began with roughly 200 cannonballs aboard, compared with the encounter’s recommendation of 60. That larger supply provided considerable room for missed shots while learning the tower’s attack windows; it was not the amount required to defeat the boss.

The encounter ended after the tentacles were destroyed and the exposed weak point was attacked. A heavily expanded ship or coordinated crew was not necessary for that clear. Your immediate concern should be maintaining a usable firing angle and enough ammunition to finish the remaining targets.

Is a Personal Ranged Weapon Better Than a Cannon?

A strong personal ranged build can also damage Calamity Tower targets. In one encounter, a bow-centered setup dealt enough damage that the player preferred it to the ship’s installed cannons. Other successful clears relied on ship weapons.

Those outcomes do not establish that one weapon category is universally stronger. The comparison depends on your available equipment and the damage you can actually produce.

For an early clear, a working cannon remains the straightforward option because the encounter takes place around your ship. A powerful personal weapon can be useful when it has a clear angle on a vulnerable target, but there is little value in abandoning a reliable setup solely because a different build performs better for another player.

Long Lament: How to Prepare for the Second Tower

Long Lament appears later in the main quest, after the Reefshadow Bay objectives have advanced. It is the next major equipment checkpoint, and completing its challenge unlocks Tier 3 Gear Crafting.

By the time the quest directs you there, ordinary sailing and naval combat may already have damaged your vessel or consumed a significant amount of ammunition. Restock before beginning the encounter rather than sailing directly from the previous fight.

A successful Long Lament preparation sequence involved building additional ship weapons, manufacturing cannonballs, and repairing the vessel before entering the challenge.

There are two useful ways to approach the fight, depending on what you already have.

A basic cannon setup can still work when its placement allows you to attack the tentacles consistently. Rapid Fire Cannons are another option once available, especially when you want a more responsive shipboard weapon. The presence of a more advanced cannon does not remove the need to expose and hit the tower’s vulnerable structure.

The critical preparation is having weapons you can operate from the positions the battle requires.

Keep a Clear Shot During Long Lament

Long Lament’s tentacles move around the tower, so a firing angle that worked on one target may not work on the next. Steer to bring the active target into view and avoid firing into your own ship’s structures.

If the sail repeatedly blocks your aim, adjust its placement and the cannon layout before another attempt. The Ship Building instructions explain how to keep the firing position clear.

How to Claim Calamity Tower Rewards After the Fight

Defeating the creature is not the last action.

When the tower dies, follow the beam down toward its base and locate the reward container. Open it and collect the rewards before exiting the encounter.

This can be easy to overlook if you are still aboard your ship and expecting the equipment unlock to finish automatically.

1. Finish the fight and wait for the new objective.
2. Follow the beam toward the tower’s base.
3. Bring your vessel close enough to disembark safely.
4. Locate the reward container, shown during an early clear as a Dusty Loot Crate.
5. Open the container and claim the rewards.
6. Exit the encounter once the collection objective is complete.

An early Sunken Oath clear awarded items including equipment-related rewards, Tech Points, Battle Experience, and Energy Links. The exact reward contents may differ with the tower and encounter conditions.

Do not leave immediately after destroying the final weak point. Confirm that you have collected the reward and completed the relevant objective first.

What Does Long Lament Unlock?

A completed Long Lament challenge has shown the message Gear Crafting Unlocked: Crafting Tier 3, alongside Tier 3 equipment rewards and a memory fragment.

That is the immediate equipment progression milestone. The main quest then continues through the recovered memory and points toward Misty Marsh.

Unlocking Tier 3 does not mean every Tier 3 weapon or armor piece becomes craftable without further preparation. The Tech Progression guide explains the separate research, materials, and crafting requirements.

Why Is Your Calamity Tower Not Completing?

Several encounter states can look similar from aboard your ship, but they require different actions.

The tower is still attacking despite destroyed tentacles. Check for another active tentacle or an exposed weak point. During Long Lament, the remaining target was not immediately visible from one firing angle, requiring the player to look around before continuing.

Your cannon fires but cannot reach the target. Inspect its line of fire. Large sails and ship structures can obstruct the shot even when the tower is nearby. Reposition the vessel or correct the weapon layout rather than continuing to fire into the obstruction.

The boss is dead, but the task is still active. Follow the beam toward the base and collect the reward. Killing the tower and opening the post-battle loot are separate actions.

The tower is already defeated on the server, but your mission remains incomplete. Follow your current quest marker and complete the associated encounter for your character. Another player’s earlier clear does not replace your own required progression.

You have finished the fight but cannot make the newly unlocked equipment. Check the remaining Tech and crafting requirements instead of repeating the same tower solely to unlock the tier again.

Once the reward is collected, leave the encounter and continue the main quest. Sunken Oath leads into the Reefshadow Bay objectives; Long Lament moves the story toward Misty Marsh. The Isles of Abyss progression walkthrough follows those tasks in order.