Stop The Tsunami Upgrade Machines and Gear

Coins in Stop The Tsunami! exist to buy time. Better tools dig faster, grade smoother, haul more, and let you pack a longer wall before you press START ROUND. This guide covers the full machine ladder — toy spade → shovels → bulldozer → skid steer → excavators → dump truck — plus coin priorities and the moment heavy machines stop being optional. Cross-check rankings on the machine tier list, learn the early loop in Getting Started, and bring the right fleet into Hard Mode and co-op.

Why upgrades matter

After you clear stages the beach widens and waves grow. A wall that held on a short Easy shoreline will not span the new approach if you still scoop with a toy spade. Upgrades are how dig volume and material transport scale with map length. Skipping them feels thrifty for one round and expensive for the next ten.

The progression ladder

Toy spade

Starter tool. Fine for learning dig → pile → pack on Easy. Replace it as soon as you can afford a shovel. Keeping the toy spade “to save coins” is the most common early trap.

Shovels

Your first real throughput jump. Shovels dig faster and feed wall piles before the mental timer forces a bad START ROUND. Buy a shovel before any cosmetic flex. Solo and co-op alike should treat shovel ownership as non-negotiable day-one gear.

Bulldozer

The bulldozer turns piles into shaped berms. It shines when you need to push mass along the wall line, flatten uneven crests, and reclaim scattered sand. Unlock it once shovel clears feel comfortable and Medium walls start demanding length over height spikes.

Skid steer

Agile grading and patch support. Skid steers help when the wall needs quick corrections, trench cleanup, or ferrying material to a flank that is falling behind. In co-op, a skid steer driver often plays midfield between diggers and packers.

Excavators

Excavators matter when beaches are wide and Hard materials enter the build. High dig volume keeps gravel, clay, and concrete projects fed. If your wall length doubles but dig rate stays shovel-tier, you will start rounds half-finished.

Dump truck

Late logistics king. The dump truck moves bulk material across the widened beach so one rich dig site can supply the whole line. Pair it with excavators: one digs, one hauls, one packs — the same role logic as co-op even if you rotate seats solo.

Coin priorities (spend order)

Use this order unless a patch note radically retunes prices:

1. Shovel — mandatory exit from toy spade.
2. Second dig upgrade / better shovel tier if available before heavy machines.
3. Bulldozer — shape and push for Medium length walls.
4. Skid steer — mobility and patch assists.
5. Excavators — volume for wide beaches and Hard prep.
6. Dump truck — haul capacity when distance becomes the bottleneck.
7. Material unlocks (gravel, boulders, clay, concrete) timed with Hard attempts — see materials guidance inside Hard Mode.

Do not starve the shovel to rush a dump truck. A parked truck with no dig feed is a coin statue. Do not buy every machine the same session if your wall craft is still leaking; read Build Defenses and fix packing first.

When heavy machines start to matter

Heavy gear becomes essential when:

• Cleared stages have widened the beach past what shovel cycles can fill.
• You are moving from Easy comfort into Medium consistency.
• Hard runs demand stronger materials that need excavator volume and dump truck haul.
• Co-op teams idle because diggers cannot feed three builders.

If Easy still wrecks you, machines are not the main bug — packing and continuity are. Buy the shovel, then practice walls. When Easy is boring and Medium walls feel short on time, that is the bulldozer / skid steer window. When Hard materials sit unused because you cannot move them, that is excavator / dump truck time.

Solo spending vs shared wallet

Friends share one coin wallet and every machine. That changes shopping:

• Solo: You need a flexible personal ladder — shovel → dozer/skid → excavator → truck as beaches grow.
• Co-op: Specialize purchases. One excavator plus one dump truck plus pack tools beats three duplicate shovels. Assign seats with the Co-op Guide so nobody fights over the only dozer while the flank collapses.

Shared wallets punish selfish buys. Talk before dumping the team purse into a machine nobody will crew.

Session plan for upgrades

1. Clear lobby dailies and any codes.
2. Run Easy or Medium until the shovel is owned.
3. Hold several waves; bank coins deliberately.
4. Buy bulldozer or skid steer when wall length outpaces shovel time.
5. Clear stages, note beach width, then plan excavator / dump truck.
6. Recheck the machine tier list after updates in case rankings shift.

Efficiency tips

• Upgrade before a widened-beach session, not mid-panic after a wipe.
• Practice one new machine on Easy before taking it into Hard.
• Park machines on access paths, not on the wall crest you still need to pack.
• In co-op, call “truck empty” / “excavator idle” so roles stay fluid.
• Pair machine upgrades with defense skill — throughput without packing still floods.

Mistakes that waste coins

Toy spade pride. You are not saving money; you are donating rounds to the ocean.

Truck before feed. Haul without dig volume moves air.

Ignoring beach width. Old shopping lists fail on new shorelines.

Duplicate toys in co-op. Shared fleet needs coverage, not clones.

Skipping Hard material budget. Machines place materials; they do not replace them on Hard.

Related reading

• Rankings → machine tier list
• Day-one loop → Getting Started
• Using gear on brutal waves → Hard Mode
• Shared fleet roles → Co-op Guide

Spend so every held wave buys more wall per minute. When dig, grade, and haul stay ahead of beach width, START ROUND stops feeling like a coin flip.